experiment on animals morally wrong

Is animal research ethical?

Posted: by John Meredith on 16/02/22

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How can it be right to use an animal for research where we could consider it unethical to use a human being? This is a fundamental question that confronts anybody who benefits from research using animals. If we claim that causing harm to animals is sometimes justifiable where it would be unacceptable to inflict a similar harm or risk on a person, then it seems we are assuming that animals must, in some sense, have less moral value. But is that a justifiable assumption, or is it just a self-serving prejudice? Are there solid rational arguments for treating humans differently from other animals, or are we simply falling back on outmoded habits of thought, a smokescreen that helps us avoid looking the ugly truth of our actions in the eye?

Moral status of animals

In the past, the moral status of animals did not merit a great deal of consideration; raising questions about whether humans were entitled to exploit animals would have struck most people as quaint or absurd. The great moral philosopher Rene Descartes, for example, the man famous for the phrase  cogito ergo sum  - ‘I think therefore I am’ - believed that animals had no inner life at all, that they were essentially as lifeless as clockwork dolls, incapable of emotion, self-awareness, or even feeling pain.  

Such ideas seem laughable to us now. We take it for granted that most animals experience pain and many have complex emotional lives that can depend on relationships with other animals and which can deliver feelings of pleasure and satisfaction. Since Descartes’ day, the growing study of animal behaviour makes this seem obvious, and cleverly designed experiments have confirmed what has been learned from observation, forcing us to acknowledge that sentience – inner life – exists in a great number of other species and sometimes at a very high level. 

But what implications does all this have for the moral consideration of animals? How should it affect the way we treat them? Philosopher Peter Singer, whose book  Animal Liberation  transformed the public debate on animal welfare, believes it should have deep and wide-reaching consequences. Singer argues that it is wrong to inflict harm on a person not because of any cosmic or biblical law about harm but because it is against that person’s interests as they themselves understand them. Considering moral questions in that light, he argues, explodes any idea that we can justify distinctions between individuals based on their sex or race, distinctions that have been passionately defended over many centuries. There are many differences between people of all kinds including, of course, both sexes, but they all have interests that are alike: an interest in avoiding pain or hunger for example. There is no rational basis for preferring the interests of any particular individual, or people of one race or sex class over those of another, that is simply racism and sexism. This is an idea has become widely accepted, if only recently, and it doesn’t seem particularly radical to us today, but Singer takes the idea a step further. 

If there is no non-arbitrary reason to prefer the interests of one human animal over another, how can there be any good reason to prefer the interests of a human animal over a non-human animal? Claims that humans are of special moral interest because of their intelligence or capacity for language or any of the many other things that have been suggested cut no ice.  A less intelligent human has as much interest in avoiding pain as a mathematical genius does, and the same goes for a dog, or a mouse, or a fish. To deny this, says Singer is to make a moral mistake akin to sexism or racism and he calls this way of thinking  speciesism .

One objection to the argument from speciesism is that it implies that there can never be a reason to prefer the welfare of a human being over any other animal where considerations of interest are the same. This strikes most people as counter-intuitive to say the least. Jean Kazez, philosopher and animal rights activist, suggests a thought experiment. Imagine a dedicated vegan responsible for the care of ten young children. It so happens that famine strikes and the children are all in danger of starvation except that our vegan carer owns a cow. Would it be morally acceptable for the vegan to stick by her principles and refuse to slaughter the cow to save the children? If the answer is no, then there seems to be some problem with the speciesist position. It would probably not be considered acceptable to slaughter one of the children to feed the others, after all. So, our intuition is that there must be some foundation for our moral preference for a human over an animal, at least in some extreme conditions. Perhaps the intuition is that there is moral value in feelings of kinship because this is a necessary feeling in order to be a fully healthy human, to flourish as a human being. If that is the case, then, kinship, for humans, is a kind of interest in the Singer sense and one that overrides other interests. That may be why we don’t find it reprehensible when a mother prefers the welfare of her child over that of another.

The moral value of ‘kinship’ overrides speciesism

If kinship carries moral weight, then the speciesist argument loses ground and a possible justification for preferring animals over human beings in research emerges.  Medical research is an attempt to save human lives and reduce human suffering (it has similar benefits for animal as well, of course, but we can set that aside for now, for the sake of simplicity). If, as scientists argue, this can only be achieved with the use of an animal model, then we are morally entitled to prefer the use of a non-human animal, so long as kinship has the moral value we are claiming for it and the suffering and distress of the animals is minimised as much as possible.

But what if this is all just a complicated exercise in justifying what we want to do anyway, what if our moral intuitions are just wrong? It is easy to imagine a Singerian arguing, in the case of our starving children and vegan nanny, that the cow has as much moral standing as any of the others: it has the same interest in living and not suffering the pain of hunger as the others and, what’s more, it may be better able to survive the famine given its ability to eat vegetation that cannot sustain humans. In that case, it seems the advocate of speciesism must argue that they all should starve together in the interests of admirable intellectual rigour, even if it feels a little hard on the children.

Using utility to resolve moral conflicts

As usual, though, the situation is more complicated. Peter Singer and his followers recognise that there is often a conflict of moral interests and so we need a framework for finding a resolution. This framework should not be  ad hoc or arbitrary or based on scripture or any other culturally specific text or tradition but should be rational. Within Singer’s argument the rational moral grounding is provided by utilitarianism the ethical doctrine first proposed by Jeremy Bentham in the 19th century. Utilitarianism argues that when two actions are in conflict, the morally correct one is the one that delivers the most happiness for the largest number (Bentham called this ‘utility’ for obscure reasons). In other words, the morality of an action is decided by its consequences, not by the intentions of the actor or anything else. Applied to the problem of our starving infants and their increasingly paranoid cow, a utilitarian might argue that killing the cow is justified despite it having a similar interest in living to the children because the slaughter would maximise future happiness (utility). If they all die, happiness would be at zero, and if a child was sacrificed to save the others, that would reduce overall happiness because of the distress of the survivors at their loss, the suffering endured by the child selected to die, and the indifference of the cow. 

How do you measure happiness?

Problems with utilitarian ways of thinking immediately suggest themselves: how can happiness be measured? How can the ‘happiness’ of a mouse, for example, be weighed against a person, or any other animal? Must we consider a well-intentioned action that has bad outcomes immoral instead of just unfortunate? The literature goes into all these problems and more at great depth, but for our purposes, it is at least clear that a utilitarian moral framework allows for the use of research animals in some circumstances. The human happiness delivered by a successful medical treatment can be great and long lasting while any pain or distress caused to the experimental animals is kept to a minimum and is of very limited duration. In the utilitarian scales, this tips firmly towards an ethical justification of animal research. It is a surprise to many people that Peter Singer, the father of the modern animal rights movement, comes to the same conclusion, although he argues for stricter controls and more work to reduce and mitigate the use of animals. Even without appealing to concepts such as kinship, in other words, the concept of speciesism, perhaps the most formidable intellectual weapon aimed against animal research by protest groups, does not carry the day. It is perfectly possible to allow the moral value of an animal’s interests and still justify its use in research – even if that research causes the animal harm or distress – so long as the future outcomes maximise happiness. 

Animal rights arguments

The only significant ethical argument against animal research that remains is based on the idea of rights. Just as humans have inalienable rights, the argument goes, so do animals. According to this view, the use of animals for research can never be justified for exactly the same reasons that we cannot justify using humans. But argument from rights has many more problems than argument from interests: from where are rights derived? What specific rights do animals have? Should rights be protected even when this is damaging to the welfare of the animal? This last point is perhaps the most salient. If we allow an animal has a right to its freedom, say, not to be kept in captivity (one of the key rights usually claimed by activists), then we are not only committed to ending all ownership of animals, but to the immediate release of all domestic animals into the wild even if that were to the detriment of the animals’ welfare as it surely would be. The problems mount at every step. How can it be possible to reconcile a vole’s right to life with a falcon’s right to eat? What possible mechanism could be constructed to resolve such conflicts and how much irreparable harm to natural ecosystems would follow if we built one? Without answers to questions like this it is hard to see animal rights arguments as much more than rhetoric.

Maximising future happiness and minimising present suffering is enough for an ethical justification of animal research

The case for ethical animal research, then, does not need as much building as it might at first appear. None of the major philosophical arguments for animal welfare exclude the possibility of ethical animal research. The harm that is done to animals in well-regulated research environments serves a higher moral purpose: the reduction of death and suffering by disease and other disorders. Of course, this is only true if pain, suffering and distress, are minimised – as they are through animal welfare regulations in the UK and EU for example. These regulations also require the application of the principles of the 3Rs – but it is quite obvious, all other things being equal, that the use of a mouse in an investigation into cancer development, for example, will create less suffering than using a person for the same purposes. 

So, a utilitarian calculation of maximising future happiness and minimising present suffering is enough for an ethical justification of animal research even for tough minded opponents of animal exploitation such as Professor Singer. But maybe justification is the wrong word. 

Are we not morally obliged to use animals in research?

If, as the biological sciences are almost unanimous in claiming, we cannot have new medicines without some animal research, and if there are hundreds of devastating human illnesses that will continue to cause misery, pain, and heartache without those new treatments, should we not think of animal research as a moral obligation instead? It is difficult science to do, both technically and emotionally, but if we choose not to carry it out, we are effectively choosing to allow human suffering to continue in the future that our efforts today have the potential to reduce or eliminate. We don’t know which suffering we will be successful in mitigating when, but we can be certain that progress is being made. Remove animal research and we don’t not remove suffering, we simply transfer it from the animals now (where it is carefully controlled and minimised, very often to nothing) to future humans. That is the heart of the ethical case for animal research and one that needs to be better addressed by those who oppose it.

Last edited: 7 April 2022 12:16

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• J Prev Med Hyg
• v.63(2 Suppl 3); 2022 Jun

Ethical considerations regarding animal experimentation

Aysha karim kiani.

1 Allama Iqbal Open University, Islamabad, Pakistan

2 MAGI EUREGIO, Bolzano, Italy

DEREK PHEBY

3 Society and Health, Buckinghamshire New University, High Wycombe, UK

GARY HENEHAN

4 School of Food Science and Environmental Health, Technological University of Dublin, Dublin, Ireland

RICHARD BROWN

5 Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada

PAUL SIEVING

6 Department of Ophthalmology, Center for Ocular Regenerative Therapy, School of Medicine, University of California at Davis, Sacramento, CA, USA

PETER SYKORA

7 Department of Philosophy and Applied Philosophy, University of St. Cyril and Methodius, Trnava, Slovakia

ROBERT MARKS

8 Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel

BENEDETTO FALSINI

9 Institute of Ophthalmology, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario A. Gemelli-IRCCS, Rome, Italy

NATALE CAPODICASA

10 MAGI BALKANS, Tirana, Albania

STANISLAV MIERTUS

11 Department of Biotechnology, University of SS. Cyril and Methodius, Trnava, Slovakia

12 International Centre for Applied Research and Sustainable Technology, Bratislava, Slovakia

LORENZO LORUSSO

13 UOC Neurology and Stroke Unit, ASST Lecco, Merate, Italy

DANIELE DONDOSSOLA

14 Center for Preclincal Research and General and Liver Transplant Surgery Unit, Fondazione IRCCS Ca‘ Granda Ospedale Maggiore Policlinico, Milan, Italy

15 Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy

GIANLUCA MARTINO TARTAGLIA

16 Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milan, Italy

17 UOC Maxillo-Facial Surgery and Dentistry, Fondazione IRCCS Ca Granda, Ospedale Maggiore Policlinico, Milan, Italy

MAHMUT CERKEZ ERGOREN

18 Department of Medical Genetics, Faculty of Medicine, Near East University, Nicosia, Cyprus

MUNIS DUNDAR

19 Department of Medical Genetics, Erciyes University Medical Faculty, Kayseri, Turkey

SANDRO MICHELINI

20 Vascular Diagnostics and Rehabilitation Service, Marino Hospital, ASL Roma 6, Marino, Italy

DANIELE MALACARNE

21 MAGI’S LAB, Rovereto (TN), Italy

GABRIELE BONETTI

Astrit dautaj, kevin donato, maria chiara medori, tommaso beccari.

22 Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy

MICHELE SAMAJA

23 MAGI GROUP, San Felice del Benaco (BS), Italy

STEPHEN THADDEUS CONNELLY

24 San Francisco Veterans Affairs Health Care System, University of California, San Francisco, CA, USA

DONALD MARTIN

25 Univ. Grenoble Alpes, CNRS, Grenoble INP, TIMC-IMAG, SyNaBi, Grenoble, France

ASSUNTA MORRESI

26 Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy

ARIOLA BACU

27 Department of Biotechnology, University of Tirana, Tirana, Albania

KAREN L. HERBST

28 Total Lipedema Care, Beverly Hills California and Tucson Arizona, USA

MYKHAYLO KAPUSTIN

29 Federation of the Jewish Communities of Slovakia

LIBORIO STUPPIA

30 Department of Psychological, Health and Territorial Sciences, School of Medicine and Health Sciences, University "G. d'Annunzio", Chieti, Italy

LUDOVICA LUMER

31 Department of Anatomy and Developmental Biology, University College London, London, UK

GIAMPIETRO FARRONATO

Matteo bertelli.

32 MAGISNAT, Peachtree Corners (GA), USA

Animal experimentation is widely used around the world for the identification of the root causes of various diseases in humans and animals and for exploring treatment options. Among the several animal species, rats, mice and purpose-bred birds comprise almost 90% of the animals that are used for research purpose. However, growing awareness of the sentience of animals and their experience of pain and suffering has led to strong opposition to animal research among many scientists and the general public. In addition, the usefulness of extrapolating animal data to humans has been questioned. This has led to Ethical Committees’ adoption of the ‘four Rs’ principles (Reduction, Refinement, Replacement and Responsibility) as a guide when making decisions regarding animal experimentation. Some of the essential considerations for humane animal experimentation are presented in this review along with the requirement for investigator training. Due to the ethical issues surrounding the use of animals in experimentation, their use is declining in those research areas where alternative in vitro or in silico methods are available. However, so far it has not been possible to dispense with experimental animals completely and further research is needed to provide a road map to robust alternatives before their use can be fully discontinued.

How to cite this article: Kiani AK, Pheby D, Henehan G, Brown R, Sieving P, Sykora P, Marks R, Falsini B, Capodicasa N, Miertus S, Lorusso L, Dondossola D, Tartaglia GM, Ergoren MC, Dundar M, Michelini S, Malacarne D, Bonetti G, Dautaj A, Donato K, Medori MC, Beccari T, Samaja M, Connelly ST, Martin D, Morresi A, Bacu A, Herbst KL, Kapustin M, Stuppia L, Lumer L, Farronato G, Bertelli M. Ethical considerations regarding animal experimentation. J Prev Med Hyg 2022;63(suppl.3):E255-E266. https://doi.org/10.15167/2421-4248/jpmh2022.63.2S3.2768

Introduction

Animal model-based research has been performed for a very long time. Ever since the 5 th century B.C., reports of experiments involving animals have been documented, but an increase in the frequency of their utilization has been observed since the 19 th century [ 1 ]. Most institutions for medical research around the world use non-human animals as experimental subjects [ 2 ]. Such animals might be used for research experimentations to gain a better understanding of human diseases or for exploring potential treatment options [ 2 ]. Even those animals that are evolutionarily quite distant from humans, such as Drosophila melanogaster , Zebrafish ( Danio rerio ) and Caenorhabditis elegans , share physiological and genetic similarities with human beings [ 2 ]; therefore animal experimentation can be of great help for the advancement of medical science [ 2 ].

For animal experimentation, the major assumption is that the animal research will be of benefit to humans. There are many reasons that highlight the significance of animal use in biomedical research. One of the major reasons is that animals and humans share the same biological processes. In addition, vertebrates have many anatomical similarities (all vertebrates have lungs, a heart, kidneys, liver and other organs) [ 3 ]. Therefore, these similarities make certain animals more suitable for experiments and for providing basic training to young researchers and students in different fields of biological and biomedical sciences [ 3 ]. Certain animals are susceptible to various health problems that are similar to human diseases such as diabetes, cancer and heart disease [ 4 ]. Furthermore, there are genetically modified animals that are used to obtain pathological phenotypes [ 5 ]. A significant benefit of animal experimentation is that test species can be chosen that have a much shorter life cycle than humans. Therefore, animal models can be studied throughout their life span and for several successive generations, an essential element for the understanding of disease progression along with its interaction with the whole organism throughout its lifetime [ 6 ].

Animal models often play a critical role in helping researchers who are exploring the efficacy and safety of potential medical treatments and drugs. They help to identify any dangerous or undesired side effects, such as birth defects, infertility, toxicity, liver damage or any potential carcinogenic effects [ 7 ]. Currently, U.S. Federal law, for example, requires that non-human animal research is used to demonstrate the efficacy and safety of any new treatment options before proceeding to trials on humans [ 8 ]. Of course, it is not only humans benefit from this research and testing, since many of the drugs and treatments that are developed for humans are routinely used in veterinary clinics, which help animals live longer and healthier lives [ 4 ].

COVID-19 AND THE NEED FOR ANIMAL MODELS

When COVID-19 struck, there was a desperate need for research on the disease, its effects on the brain and body and on the development of new treatments for patients with the disease. Early in the disease it was noticed that those with the disease suffered a loss of smell and taste, as well as neurological and psychiatric symptoms, some of which lasted long after the patients had “survived” the disease [ 9-15 ]. As soon as the pandemic started, there was a search for appropriate animal models in which to study this unknown disease [ 16 , 17 ]. While genetically modified mice and rats are the basic animal models for neurological and immunological research [ 18 , 19 ] the need to understand COVID-19 led to a range of animal models; from fruit flies [ 20 ] and Zebrafish [ 21 ] to large mammals [ 22 , 23 ] and primates [ 24 , 25 ]. And it was just not one animal model that was needed, but many, because different aspects of the disease are best studied in different animal models [ 16 , 25 , 26 ]. There is also a need to study the transmission pathways of the zoonosis: where does it come from, what are the animal hosts and how is it transferred to humans [ 27 ]?

There has been a need for animal models for understanding the pathophysiology of COVID-19 [ 28 ], for studying the mechanisms of transmission of the disease [ 16 ], for studying its neurobiology [ 29 , 30 ] and for developing new vaccines [ 31 ]. The sudden onset of the COVID-19 pandemic has highlighted the fact that animal research is necessary, and that the curtailment of such research has serious consequences for the health of both humans and animals, both wild and domestic [ 32 ] As highlighted by Adhikary et al. [ 22 ] and Genzel et al. [ 33 ] the coronavirus has made clear the necessity for animal research and the danger in surviving future such pandemics if animal research is not fully supported. Genzel et al. [ 33 ], in particular, take issue with the proposal for a European ban on animal testing. Finally, there is a danger in bypassing animal research in developing new vaccines for diseases such as COVID-19 [ 34 ]. The purpose of this paper is to show that, while animal research is necessary for the health of both humans and animals, there is a need to carry out such experimentation in a controlled and humane manner. The use of alternatives to animal research such as cultured human cells and computer modeling may be a useful adjunct to animal studies but will require that such methods are more readily accessible to researchers and are not a replacement for animal experimentation.

Pros and cons of animal experimentation

Arguments against animal experimentation.

A fundamental question surrounding this debate is to ask whether it is appropriate to use animals for medical research. Is our acceptance that animals have a morally lower value or standard of life just a case of speciesism [ 35 ]? Nowadays, most people agree that animals have a moral status and that needlessly hurting or abusing pets or other animals is unacceptable. This represents something of a change from the historical point of view where animals did not have any moral status and the treatment of animals was mostly subservient to maintaining the health and dignity of humans [ 36 ].

Animal rights advocates strongly argue that the moral status of non-human animals is similar to that of humans, and that animals are entitled to equality of treatment. In this view, animals should be treated with the same level of respect as humans, and no one should have the right to force them into any service or to kill them or use them for their own goals. One aspect of this argument claims that moral status depends upon the capacity to suffer or enjoy life [ 37 ].

In terms of suffering and the capacity of enjoying life, many animals are not very different from human beings, as they can feel pain and experience pleasure [ 38 ]. Hence, they should be given the same moral status as humans and deserve equivalent treatment. Supporters of this argument point out that according animals a lower moral status than humans is a type of prejudice known as “speciesism” [ 38 ]. Among humans, it is widely accepted that being a part of a specific race or of a specific gender does not provide the right to ascribe a lower moral status to the outsiders. Many advocates of animal rights deploy the same argument, that being human does not give us sufficient grounds declare animals as being morally less significant [ 36 ].

ARGUMENTS IN FAVOR OF ANIMAL EXPERIMENTATION

Those who support animal experimentation have frequently made the argument that animals cannot be elevated to be seen as morally equal to humans [ 39 ]. Their main argument is that the use of the terms “moral status” or “morality” is debatable. They emphasize that we must not make the error of defining a quality or capacity associated with an animal by using the same adjectives used for humans [ 39 ]. Since, for the most part, animals do not possess humans’ cognitive capabilities and lack full autonomy (animals do not appear to rationally pursue specific goals in life), it is argued that therefore, they cannot be included in the moral community [ 39 ]. It follows from this line of argument that, if animals do not possess the same rights as human beings, their use in research experimentation can be considered appropriate [ 40 ]. The European and the American legislation support this kind of approach as much as their welfare is respected.

Another aspect of this argument is that the benefits to human beings of animal experimentation compensate for the harm caused to animals by these experiments.

In other words, animal harm is morally insignificant compared to the potential benefits to humans. Essentially, supporters of animal experimentation claim that human beings have a higher moral status than animals and that animals lack certain fundamental rights accorded to humans. The potential violations of animal rights during animal research are, in this way, justified by the greater benefits to mankind [ 40 , 41 ]. A way to evaluate when the experiments are morally justified was published in 1986 by Bateson, which developed the Bateson’s Cube [ 42 ]. The Cube has three axes: suffering, certainty of benefit and quality of research. If the research is high-quality, beneficial, and not inflicting suffering, it will be acceptable. At the contrary, painful, low-quality research with lower likelihood of success will not be acceptable [ 42 , 43 ].

Impact of experimentations on animals

Ability to feel pain and distress.

Like humans, animal have certain physical as well as psychological characteristics that make their use for experimentation controversial [ 44 ].

In the last few decades, many studies have increased knowledge of animal awareness and sentience: they indicate that animals have greater potential to experience damage than previously appreciated and that current rights and protections need to be reconsidered [ 45 ]. In recent times, scientists as well as ethicists have broadly acknowledged that animals can also experience distress and pain [ 46 ]. Potential sources of such harm arising from their use in research include disease, basic physiological needs deprivation and invasive procedures [ 46 ]. Moreover, social deprivation and lack of the ability to carry out their natural behaviors are other causes of animal harm [ 46 ]. Several studies have shown that, even in response to very gentle handling and management, animals can show marked alterations in their physiological and hormonal stress markers [ 47 ].

In spite of the fact that suffering and pain are personalized experiences, several multi-disciplinary studies have provided clear evidence of animals experiencing pain and distress. In particular, some animal species have the ability to express pain similarly to human due to common psychological, neuroanatomical and genetic characteristics [ 48 ]. Similarly, animals share a resemblance to humans in their developmental, genetic and environmental risk factors for psychopathology. For instance, in many species, it has been shown that fear operates within a less organized subcortical neural circuit than pain [ 49 , 50 ]. Various types of depression and anxiety disorders like posttraumatic stress disorder have also been reported in mammals [ 51 ].

PSYCHOLOGICAL CAPABILITIES OF ANIMALS

Some researchers have suggested that besides their ability to experience physical and psychological pain and distress, some animals also exhibit empathy, self-awareness and language-like capabilities. They also demonstrate tools-linked cognizance, pleasure-seeking and advanced problem-solving skills [ 52 ]. Moreover, mammals and birds exhibit playful behavior, an indicator of the capacity to experience pleasure. Other taxa such as reptiles, cephalopods and fishes have also been observed to display playful behavior, therefore the current legislation prescribes the use of environmental enrichers [ 53 ]. The presence of self-awareness ability, as assessed by mirror self-recognition, has been reported in magpies, chimpanzees and other apes, and certain cetaceans [ 54 ]. Recently, another study has revealed that crows have the ability to create and use tools that involve episodic-like memory formation and its retrieval. From these findings, it may be suggested that crows as well as related species show evidence of flexible learning strategies, causal reasoning, prospection and imagination that are similar to behavior observed in great apes [ 55 ]. In the context of resolving the ethical dilemmas about animal experimentation, these observations serve to highlight the challenges involved [ 56 , 57 ].

Ethics, principles and legislation in animal experimentation

Ethics in animal experimentation.

Legislation around animal research is based on the idea of the moral acceptability of the proposed experiments under specific conditions [ 58 ]. The significance of research ethics that ensures proper treatment of experimental animals [ 58 ]. To avoid undue suffering of animals, it is important to follow ethical considerations during animal studies [ 1 ]. It is important to provide best human care to these animals from the ethical and scientific point of view [ 1 ]. Poor animal care can lead to experimental outcomes [ 1 ]. Thus, if experimental animals mistreated, the scientific knowledge and conclusions obtained from experiments may be compromised and may be difficult to replicate, a hallmark of scientific research [ 1 ]. At present, most ethical guidelines work on the assumption that animal experimentation is justified because of the significant potential benefits to human beings. These guidelines are often permissive of animal experimentation regardless of the damage to the animal as long as human benefits are achieved [ 59 ].

PRINCIPLE OF THE 4 RS

Although animal experimentation has resulted in many discoveries and helped in the understanding numerous aspects of biological science, its use in various sectors is strictly controlled. In practice, the proposed set of animal experiments is usually considered by a multidisciplinary Ethics Committee before work can commence [ 60 ]. This committee will review the research protocol and make a judgment as to its sustainability. National and international laws govern the utilization of animal experimentation during research and these laws are mostly based on the universal doctrine presented by Russell and Burch (1959) known as principle of the 3 Rs. The 3Rs referred to are Reduction, Refinement and Replacement, and are applied to protocols surrounding the use of animals in research. Some researchers have proposed another “R”, of responsibility for the experimental animal as well as for the social and scientific status of the animal experiments [ 61 ]. Thus, animal ethics committees commonly review research projects with reference to the 4 Rs principles [ 62 ].

The first “R”, Reduction means that the experimental design is examined to ensure that researchers have reduced the number of experimental animals in a research project to the minimum required for reliable data [ 59 ]. Methods used for this purpose include improved experimental design, extensive literature search to avoid duplication of experiments [ 35 ], use of advanced imaging techniques, sharing resources and data, and appropriate statistical data analysis that reduce the number of animals needed for statistically significant results [ 2 , 63 ].

The second “R”, Refinement involves improvements in procedure that minimize the harmful effects of the proposed experiments on the animals involved, such as reducing pain, distress and suffering in a manner that leads to a general improvement in animal welfare. This might include for example improved living conditions for research animals, proper training of people handling animals, application of anesthesia and analgesia when required and the need for euthanasia of the animals at the end of the experiment to curtail their suffering [ 63 ].

The third “R”, Replacement refers to approaches that replace or avoid the use of experimental animals altogether. These approaches involve use of in silico methods/computerized techniques/software and in vitro methods like cell and tissue culture testing, as well as relative replacement methods by use of invertebrates like nematode worms, fruit flies and microorganisms in place of vertebrates and higher animals [ 1 ]. Examples of proper application of these first “3R2 principles are the use of alternative sources of blood, the exploitation of commercially used animals for scientific research, a proper training without use of animals and the use of specimen from previous experiments for further researches [ 64-67 ].

The fourth “R”, Responsibility refers to concerns around promoting animal welfare by improvements in experimental animals’ social life, development of advanced scientific methods for objectively determining sentience, consciousness, experience of pain and intelligence in the animal kingdom, as well as effective involvement in the professionalization of the public discussion on animal ethics [ 68 ].

OTHER ASPECTS OF ANIMAL RESEARCH ETHICS

Other research ethics considerations include having a clear rationale and reasoning for the use of animals in a research project. Researchers must have reasonable expectation of generating useful data from the proposed experiment. Moreover, the research study should be designed in such a way that it should involve the lowest possible sample size of experimental animals while producing statistically significant results [ 35 ].

All individual researchers that handle experimental animals should be properly trained for handling the particular species involved in the research study. The animal’s pain, suffering and discomfort should be minimized [ 69 ]. Animals should be given proper anesthesia when required and surgical procedures should not be repeated on same animal whenever possible [ 69 ]. The procedure of humane handling and care of experimental animals should be explicitly detailed in the research study protocol. Moreover, whenever required, aseptic techniques should be properly followed [ 70 ]. During the research, anesthetization and surgical procedures on experimental animals should only be performed by professionally skilled individuals [ 69 ].

The Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines that are issued by the National Center for the Replacement, Refinement, and Reduction of Animals in Research (NC3Rs) are designed to improve the documentation surrounding research involving experimental animals [ 70 ]. The checklist provided includes the information required in the various sections of the manuscript i.e. study design, ethical statements, experimental procedures, experimental animals and their housing and husbandry, and more [ 70 ].

It is critical to follow the highest ethical standards while performing animal experiments. Indeed, most of the journals refuse to publish any research data that lack proper ethical considerations [ 35 ].

INVESTIGATORS’ ETHICS

Since animals have sensitivity level similar to the human beings in terms of pain, anguish, survival instinct and memory, it is the responsibility of the investigator to closely monitor the animals that are used and identify any sign of distress [ 71 ]. No justification can rationalize the absence of anesthesia or analgesia in animals that undergo invasive surgery during the research [ 72 ]. Investigators are also responsible for giving high-quality care to the experimental animals, including the supply of a nutritious diet, easy water access, prevention of and relief from any pain, disease and injury, and appropriate housing facilities for the animal species [ 73 ]. A research experiment is not permitted if the damage caused to the animal exceeds the value of knowledge gained by that experiment. No scientific advancement based on the destruction and sufferings of another living being could be justified. Besides ensuring the welfare of animals involved, investigators must also follow the applicable legislation [ 74 , 75 ].

To promote the comfort of experimental animals in England, an animal protection society named: ‘The Society for the Preservation of Cruelty to Animals’ (now the Royal Society for the Prevention of Cruelty to Animals) was established (1824) that aims to prevent cruelty to animal [ 76 ].

ANIMAL WELFARE LAWS

Legislation for animal protection during research has long been established. In 1876 the British Parliament sanctioned the ‘Cruelty to Animals Act’ for animal protection. Russell and Burch (1959) presented the ‘3 Rs’ principles: Replacement, Reduction and Refinement, for use of animals during research [ 61 ]. Almost seven years later, the U.S.A also adopted regulations for the protection of experimental animals by enacting the Laboratory Animal Welfare Act of 1966 [ 60 ]. In Brazil, the Arouca Law (Law No. 11,794/08) regulates the animal use in scientific research experiments [ 76 ].

These laws define the breeding conditions, and regulate the use of animals for scientific research and teaching purposes. Such legal provisions control the use of anesthesia, analgesia or sedation in experiments that could cause distress or pain to experimental animals [ 59 , 76 ]. These laws also stress the need for euthanasia when an experiment is finished, or even during the experiment if there is any intense suffering for the experimental animal [ 76 ].

Several national and international organizations have been established to develop alternative techniques so that animal experimentation can be avoided, such as the UK-based National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) ( www.caat.jhsph.edu ), the European Centre for the Validation of Alternative Methods (ECVAM) [ 77 ], the Universities Federation for Animal Welfare (UFAW) ( www.ufaw.org.uk ), The Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) [ 78 ], and The Center for Alternatives to Animal Testing (CAAT) ( www.caat.jhsph.edu ). The Brazilian ‘Arouca Law’ also constitutes a milestone, as it has created the ‘National Council for the Control of Animal Experimentation’ (CONCEA) that deals with the legal and ethical issues related to the use of experimental animals during scientific research [ 76 ].

Although national as well as international laws and guidelines have provided basic protections for experimental animals, the current regulations have some significant discrepancies. In the U.S., the Animal Welfare Act excludes rats, mice and purpose-bred birds, even though these species comprise almost 90% of the animals that are used for research purpose [ 79 ]. On the other hand, certain cats and dogs are getting special attention along with extra protection. While the U.S. Animal Welfare Act ignores birds, mice and rats, the U.S. guidelines that control research performed using federal funding ensure protections for all vertebrates [ 79 , 80 ].

Living conditions of animals

Choice of the animal model.

Based on all the above laws and regulations and in line with the deliberations of ethical committees, every researcher must follow certain rules when dealing with animal models.

Before starting any experimental work, thorough research should be carried out during the study design phase so that the unnecessary use of experimental animals is avoided. Nevertheless, certain research studies may have compelling reasons for the use of animal models, such as the investigation of human diseases and toxicity tests. Moreover, animals are also widely used in the training of health professionals as well as in training doctors in surgical skills [ 1 , 81 ].

Researcher should be well aware of the specific traits of the animal species they intend to use in the experiment, such as its developmental stages, physiology, nutritional needs, reproductive characteristics and specific behaviors. Animal models should be selected on the basis of the study design and the biological relevance of the animal [ 1 ].

Typically, in early research, non-mammalian models are used to get rapid insights into research problems such as the identification of gene function or the recognition of novel therapeutic options. Thus, in biomedical and biological research, among the most commonly used model organisms are the Zebrafish, the fruit fly Drosophila melanogaster and the nematode Caenorhabditis elegans . The main advantage of these non-mammalian animal models is their prolific reproducibility along with their much shorter generation time. They can be easily grown in any laboratory setting, are less expensive than the murine animal models and are somewhat more powerful than the tissue and cell culture approaches [ 82 ].

Caenorhabditis elegans is a small-sized nematode with a short life cycle and that exists in large populations and is relatively inexpensive to cultivate. Scientists have gathered extensive knowledge of the genomics and genetics of Caenorhabditis elegans ; but Caenorhabditis elegans models, while very useful in some respects, are unable to represent all signaling pathways found in humans. Furthermore, due to its short life cycle, scientists are unable to investigate long term effects of test compounds or to analyze primary versus secondary effects [ 6 ].

Similarly, the fruit fly Drosophila melanogaster has played a key role in numerous biomedical discoveries. It is small in size, has a short life cycle and large population size, is relatively inexpensive to breed, and extensive genomics and genetics information is available [ 6 ]. However, its respiratory, cardiovascular and nervous systems differ considerably from human beings. In addition, its immune system is less developed when compared to vertebrates, which is why effectiveness of a drug in Drosophila melanogaster may not be easily extrapolated to humans [ 83 ].

The Zebrafish ( Danio rerio ) is a small freshwater teleost, with transparent embryos, providing easy access for the observation of organogenesis and its manipulation. Therefore, Zebrafish embryos are considered good animal models for different human diseases like tuberculosis and fetal alcohol syndrome and are useful as neurodevelopmental research models. However, Zebrafish has very few mutant strains available, and its genome has numerous duplicate genes making it impossible to create knockout strains, since disrupting one copy of the gene will not disrupt the second copy of that gene. This feature limits the use of Zebrafish as animal models to study human diseases. Additionally they are rather expensive, have long life cycle, and genomics and genetics studies are still in progress [ 82 , 84 ].

Thus, experimentation on these three animals might not be equivalent to experimentation on mammals. Mammalian animal model are most similar to human beings, so targeted gene replacement is possible. Traditionally, mammals like monkey and mice have been the preferred animal models for biomedical research because of their evolutionary closeness to humans. Rodents, particularly mice and rats, are the most frequently used animal models for scientific research. Rats are the most suitable animal model for the study of obesity, shock, peritonitis, sepsis, cancer, intestinal operations, spleen, gastric ulcers, mononuclear phagocytic system, organ transplantations and wound healing. Mice are more suitable for studying burns, megacolon, shock, cancer, obesity, and sepsis as mentioned previously [ 85 ].

Similarly, pigs are mostly used for stomach, liver and transplantation studies, while rabbits are suitable for the study of immunology, inflammation, vascular biology, shock, colitis and transplantations. Thus, the choice of experimental animal mainly depends upon the field of scientific research under consideration [ 1 ].

HOUSING AND ENVIRONMENTAL ENRICHMENT

Researchers should be aware of the environment and conditions in which laboratory animals are kept during research, and they also need to be familiar with the metabolism of the animals kept in vivarium, since their metabolism can easily be altered by different factors such as pain, stress, confinement, lack of sunlight, etc. Housing conditions alter animal behavior, and this can in turn affect experimental results. By contrast, handling procedures that feature environmental enrichment and enhancement help to decrease stress and positively affect the welfare of the animals and the reliability of research data [ 74 , 75 ].

In animals, distress- and agony-causing factors should be controlled or eliminated to overcome any interference with data collection as well as with interpretation of the results, since impaired animal welfare leads to more animal usage during experiment, decreased reliability and increased discrepancies in results along with the unnecessary consumption of animal lives [ 86 ].

To reduce the variation or discrepancies in experimental data caused by various environmental factors, experimental animals must be kept in an appropriate and safe place. In addition, it is necessary to keep all variables like humidity, airflow and temperature at levels suitable for those species, as any abrupt variation in these factors could cause stress, reduced resistance and increased susceptibility to infections [ 74 ].

The space allotted to experimental animals should permit them free movement, proper sleep and where feasible allow for interaction with other animals of the same species. Mice and rats are quite sociable animals and must, therefore, be housed in groups for the expression of their normal behavior. Usually, laboratory cages are not appropriate for the behavioral needs of the animals. Therefore, environmental enrichment is an important feature for the expression of their natural behavior that will subsequently affect their defense mechanisms and physiology [ 87 ].

The features of environmental enrichment must satisfy the animals’ sense of curiosity, offer them fun activities, and also permit them to fulfill their behavioral and physiological needs. These needs include exploring, hiding, building nests and gnawing. For this purpose, different things can be used in their environment, such as PVC tubes, cardboard, igloos, paper towel, cotton, disposable masks and paper strips [ 87 ].

The environment used for housing of animals must be continuously controlled by appropriate disinfection, hygiene protocols, sterilization and sanitation processes. These steps lead to a reduction in the occurrence of various infectious agents that often found in vivarium, such as Sendai virus, cestoda and Mycoplasma pulmonis [ 88 ].

Euthanasia is a term derived from Greek, and it means a death without any suffering. According to the Brazilian Arouca Law (Article 14, Chapter IV, Paragraphs 1 and 2), an animal should undergo euthanasia, in strict compliance with the requirements of each species, when the experiment ends or during any phase of the experiment, wherever this procedure is recommended and/or whenever serious suffering occurs. If the animal does not undergo euthanasia after the intervention it may leave the vivarium and be assigned to suitable people or to the animal protection bodies, duly legalized [ 1 ].

Euthanasia procedures must result in instant loss of consciousness which leads to respiratory or cardiac arrest as well as to complete brain function impairment. Another important aspect of this procedure is calm handling of the animal while taking it out of its enclosure, to reduce its distress, suffering, anxiety and fear. In every research project, the study design should include the details of the appropriate endpoints of these experimental animals, and also the methods that will be adopted. It is important to determine the appropriate method of euthanasia for the animal being used. Another important point is that, after completing the euthanasia procedure, the animal’s death should be absolutely confirmed before discarding their bodies [ 87 , 89 ].

Relevance of animal experimentations and possible alternatives

Relevance of animal experiments and their adverse effects on human health.

One important concern is whether human diseases, when inflicted on experimental animals, adequately mimic the progressions of the disease and the treatment responses observed in humans. Several research articles have made comparisons between human and animal data, and indicated that the results of animals’ research could not always be reliably replicated in clinical research among humans. The latest systematic reviews about the treatment of different clinical conditions including neurology, vascular diseases and others, have established that the results of animal studies cannot properly predict human outcomes [ 59 , 90 ].

At present, the reliability of animal experiments for extrapolation to human health is questionable. Harmful effects may occur in humans because of misleading results from research conducted on animals. For instance, during the late fifties, a sedative drug, thalidomide, was prescribed for pregnant women, but some of the women using that drug gave birth to babies lacking limbs or with foreshortened limbs, a condition called phocomelia. When thalidomide had been tested on almost all animal models such as rats, mice, rabbits, dogs, cats, hamsters, armadillos, ferrets, swine, guinea pig, etc., this teratogenic effect was observed only occasionally [ 91 ]. Similarly, in 2006, the compound TGN 1412 was designed as an immunomodulatory drug, but when it was injected into six human volunteer, serious adverse reactions were observed resulting from a deadly cytokine storm that in turn led to disastrous systemic organ failure. TGN 1412 had been tested successfully in rats, mice, rabbits, and non-human primates [ 92 ]. Moreover, Bailey (2008) reported 90 HIV vaccines that had successful trial results in animals but which failed in human beings [ 93 ]. Moreover, in Parkinson disease, many therapeutic options that have shown promising results in rats and non-human primate models have proved harmful in humans. Hence, to analyze the relevance of animal research to human health, the efficacy of animal experimentation should be examined systematically [ 94 , 95 ]. At the same time, the development of hyperoxaluria and renal failure (up to dialysis) after ileal-jejunal bypass was unexpected because this procedure was not preliminarily evaluated on an animal model [ 96 ].

Several factors play a role in the extrapolation of animal-derived data to humans, such as environmental conditions and physiological parameters related to stress, age of the experimental animals, etc. These factors could switch on or off genes in the animal models that are specific to species and/or strains. All these observations challenge the reliability and suitability of animal experimentation as well as its objectives with respect to human health [ 76 , 92 ].

ALTERNATIVE TO ANIMAL EXPERIMENTATION/DEVELOPMENT OF NEW PRODUCTS AND TECHNIQUES TO AVOID ANIMAL SACRIFICE IN RESEARCH

Certainly, in vivo animal experimentation has significantly contributed to the development of biological and biomedical research. However it has the limitations of strict ethical issues and high production cost. Some scientists consider animal testing an ineffective and immoral practice and therefore prefer alternative techniques to be used instead of animal experimentation. These alternative methods involve in vitro experiments and ex vivo models like cell and tissue cultures, use of plants and vegetables, non-invasive human clinical studies, use of corpses for studies, use of microorganisms or other simpler organism like shrimps and water flea larvae, physicochemical techniques, educational software, computer simulations, mathematical models and nanotechnology [ 97 ]. These methods and techniques are cost-effective and could efficiently replace animal models. They could therefore, contribute to animal welfare and to the development of new therapies that can identify the therapeutics and related complications at an early stage [ 1 ].

The National Research Council (UK) suggested a shift from the animal models toward computational models, as well as high-content and high-throughput in vitro methods. Their reports highlighted that these alternative methods could produce predictive data more affordably, accurately and quickly than the traditional in vivo or experimental animal methods [ 98 ].

Increasingly, scientists and the review boards have to assess whether addressing a research question using the applied techniques of advanced genetics, molecular, computational and cell biology, and biochemistry could be used to replace animal experiments [ 59 ]. It must be remembered that each alternative method must be first validated and then registered in dedicated databases.

An additional relevant concern is how precisely animal data can mirror relevant epigenetic changes and human genetic variability. Langley and his colleagues have highlighted some of the examples of existing and some emerging non-animal based research methods in the advanced fields of neurology, orthodontics, infectious diseases, immunology, endocrine, pulmonology, obstetrics, metabolism and cardiology [ 99 ].

IN SILICO SIMULATIONS AND INFORMATICS

Several computer models have been built to study cardiovascular risk and atherosclerotic plaque build-up, to model human metabolism, to evaluate drug toxicity and to address other questions that were previously approached by testing in animals [ 100 ].

Computer simulations can potentially decrease the number of experiments required for a research project, however simulations cannot completely replace laboratory experiments. Unfortunately, not all the principles regulating biological systems are known, and computer simulation provide only an estimation of possible effects due to the limitations of computer models in comparison with complex human tissues. However, simulation and bio-informatics are now considered essential in all fields of science for their efficiency in using the existing knowledge for further experimental designs [ 76 ].

At present, biological macromolecules are regularly simulated at various levels of detail, to predict their response and behavior under certain physical conditions, chemical exposures and stimulations. Computational and bioinformatic simulations have significantly reduced the number of animals sacrificed during drug discovery by short listing potential candidate molecules for a drug. Likewise, computer simulations have decreased the number of animal experiments required in other areas of biological science by efficiently using the existing knowledge. Moreover, the development of high definition 3D computer models for anatomy with enhanced level of detail, it may make it possible to reduce or eliminate the need for animal dissection during teaching [ 101 , 102 ].

3D CELL-CULTURE MODELS AND ORGANS-ON-CHIPS

In the current scenario of rapid advancement in the life sciences, certain tissue models can be built using 3D cell culture technology. Indeed, there are some organs on micro-scale chip models used for mimicking the human body environment. 3D models of multiple organ systems such as heart, liver, skin, muscle, testis, brain, gut, bone marrow, lungs and kidney, in addition to individual organs, have been created in microfluidic channels, re-creating the physiological chemical and physical microenvironments of the body [ 103 ]. These emerging techniques, such as the biomedical/biological microelectromechanical system (Bio-MEMS) or lab-on-a-chip (LOC) and micro total analysis systems (lTAS) will, in the future, be a useful substitute for animal experimentation in commercial laboratories in the biotechnology, environmental safety, chemistry and pharmaceutical industries. For 3D cell culture modeling, cells are grown in 3D spheroids or aggregates with the help of a scaffold or matrix, or sometimes using a scaffold-free method. The 3D cell culture modeling conditions can be altered to add proteins and other factors that are found in a tumor microenvironment, for example, or in particular tissues. These matrices contain extracellular matrix components such as proteins, glycoconjugates and glycosaminoglycans that allow for cell communication, cell to cell contact and the activation of signaling pathways in such a way that the morphological and functional differentiation of these cells can accurately mimic their environment in vivo . This methodology, in time, will bridge the gap between in vivo and in vitro drug screening, decreasing the utilization of animal models during research [ 104 ].

ALTERNATIVES TO MICROBIAL CULTURE MEDIA AND SERUM-FREE ANIMAL CELL CULTURES

There are moves to reduce the use of animal derived products in many areas of biotechnology. Microbial culture media peptones are mostly made by the proteolysis of farmed animal meat. However, nowadays, various suppliers provide peptones extracted from yeast and plants. Although the costs of these plant-extracted peptones are the same as those of animal peptones, plant peptones are more environmentally favorable since less plant material and water are required for them to grow, compared with the food grain and fodder needed for cattle that are slaughtered for animal peptone production [ 105 ].

Human cell culture is often carried out in a medium that contains fetal calf serum, the production of which involves animal (cow) sacrifice or suffering. In fact, living pregnant cows are used and their fetuses removed to harvest the serum from the fetal blood. Fetal calf serum is used because it is a natural medium rich in all the required nutrients and significantly increases the chances of successful cell growth in culture. Scientists are striving to identify the factors and nutrients required for the growth of various types of cells, with a view to eliminating the use of calf serum. At present, most cell lines could be cultured in a chemically-synthesized medium without using animal products. Furthermore, data from chemically-synthesized media experiments may have better reproducibility than those using animal serum media, since the composition of animal serum does change from batch to batch on the basis of animals’ gender, age, health and genetic background [ 76 ].

ALTERNATIVES TO ANIMAL-DERIVED ANTIBODIES

Animal friendly affinity reagents may act as an alternative to antibodies produced, thereby removing the need for animal immunization. Typically, these antibodies are obtained in vitro by yeast, phage or ribosome display. In a recent review, a comparative analysis between animal friendly affinity reagents and animal derived-antibodies showed that the affinity reagents have superior quality, are relatively less time consuming, have more reproducibility and are more reliable and are cost-effective [ 106 , 107 ].

Conclusions

Animal experimentation led to great advancement in biological and biomedical sciences and contributed to the discovery of many drugs and treatment options. However, such experimentation may cause harm, pain and distress to the animals involved. Therefore, to perform animal experimentations, certain ethical rules and laws must be strictly followed and there should be proper justification for using animals in research projects. Furthermore, during animal experimentation the 4 Rs principles of reduction, refinement, replacement and responsibility must be followed by the researchers. Moreover, before beginning a research project, experiments should be thoroughly planned and well-designed, and should avoid unnecessary use of animals. The reliability and reproducibility of animal experiments should also be considered. Whenever possible, alternative methods to animal experimentation should be adopted, such as in vitro experimentation, cadaveric studies, and computer simulations.

While much progress has been made on reducing animal experimentation there is a need for greater awareness of alternatives to animal experiments among scientists and easier access to advanced modeling technologies. Greater research is needed to define a roadmap that will lead to the elimination of all unnecessary animal experimentation and provide a framework for adoption of reliable alternative methodologies in biomedical research.

Acknowledgements

This research was funded by the Provincia Autonoma di Bolzano in the framework of LP 15/2020 (dgp 3174/2021).

Conflicts of interest statement

Authors declare no conflict of interest.

Author's contributions

MB: study conception, editing and critical revision of the manuscript; AKK, DP, GH, RB, Paul S, Peter S, RM, BF, NC, SM, LL, DD, GMT, MCE, MD, SM, Daniele M, GB, AD, KD, MCM, TB, MS, STC, Donald M, AM, AB, KLH, MK, LS, LL, GF: literature search, editing and critical revision of the manuscript. All authors have read and approved the final manuscript.

Contributor Information

INTERNATIONAL BIOETHICS STUDY GROUP : Derek Pheby , Gary Henehan , Richard Brown , Paul Sieving , Peter Sykora , Robert Marks , Benedetto Falsini , Natale Capodicasa , Stanislav Miertus , Lorenzo Lorusso , Gianluca Martino Tartaglia , Mahmut Cerkez Ergoren , Munis Dundar , Sandro Michelini , Daniele Malacarne , Tommaso Beccari , Michele Samaja , Matteo Bertelli , Donald Martin , Assunta Morresi , Ariola Bacu , Karen L. Herbst , Mykhaylo Kapustin , Liborio Stuppia , Ludovica Lumer , and Giampietro Farronato

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13.7 Cosmos & Culture

The 'necessity' of animal research does not mean it's ethical.

Samual Garner

Diane, a 4-year-old chimpanzee, relaxes in the trees at the Chimp Haven sanctuary in Keithville, La., on Aug. 25, 2014. She is one of many chimps who have been moved here from the New Iberia Research Center in Lafayette, La. Brandon Wade/AP hide caption

Diane, a 4-year-old chimpanzee, relaxes in the trees at the Chimp Haven sanctuary in Keithville, La., on Aug. 25, 2014. She is one of many chimps who have been moved here from the New Iberia Research Center in Lafayette, La.

A few weeks ago, two prominent scientists, Hollis Cline and Mar Sanchez, wrote a brief piece in The Hill newspaper arguing that animal research is "necessary." They were prompted by the recent National Institutes of Health (NIH) decision to phase out the use of primates in controversial maternal deprivation studies.

Scientists have long been fond of claims of necessity — in fact, justifications for animal research have remained largely the same since the writings of 19th century French physiologist Claude Bernard. However, this claim is problematic for a number of reasons.

If animal research is necessary, then it is not necessary in the sense that we have to do it. Rather, it is a choice that we make, a choice that its proponents believe is a necessary means to the end of further medical advances. Such advances are undoubtedly of significant moral importance, but even if we grant the assumption that animals are necessary for medical progress, this does not equate to a moral justification.

Research with humans is necessary to medical progress, but we have set strict limits on the extent to which humans can be exposed to risk and harm in research, even though doing so has undoubtedly slowed the rate of medical progress that might otherwise be achievable. Cline and Sanchez claim that animals in research are treated "humanely and with dignity," but the reality is that the level of protection afforded to research animals is far, far less than that afforded to human participants in research. Most animals involved in research are killed at the termination of the experiment, are kept in conditions not conducive to their welfare, and are otherwise harmed in myriad and significant ways, for example through the infliction of physical injuries, infectious diseases, cancers, or psychological distress.

While nonhuman animals cannot provide consent to research participation, we have reasoned in the case of humans that an inability to consent entitles an individual to greater protection and not lesser protection. What justifies our differential treatment of humans and nonhuman animals in research? For present purposes, it isn't necessary to rehearse every possible argument for and against animal research. It is sufficient to note that very few contemporary ethicists defend the status quo of animal research and, furthermore, that the burden of proof has now shifted to those who would defend invasive animal research.

Given the state of philosophical scholarship, meeting this burden of proof will not be easy or straightforward. Perhaps the most remarkable aspect of the scientific community's frequent claims of the necessity of animal research is how thoroughly they miss the moral point. For the most part, ethical criticisms of animal research aren't even addressed — as they aren't in Cline and Sanchez's piece — and when they are, they're usually dismissed with bad arguments, like this one , that have been refuted for decades.

Further, the claim that "animal research is necessary to medical progress" assumes a strong causal connection between the two, but what data we have available cast doubt upon the robustness of this connection. Despite strong claims about the historical benefits of animal research from the scientific community, the accuracy of animal models in predicting human responses has not been evaluated sufficiently, and the lack of certain kinds of data make this evaluation especially challenging . Based on existing data, however, numerous reviews have suggested that the accuracy of animal research in predicting human health outcomes appears to be far less than what we once assumed.

Animal studies also frequently appear to be poorly designed . The predictive value of animal research might increase if study design improved, but this isn't certain. Even NIH Director Francis Collins recognized these concerns in a forward-thinking 2011 commentary , stating that, "The use of animal models for therapeutic development and target validation...may not accurately predict efficacy in humans." Given these issues, systematic reviews should become routine and strong statements about the utility of animal models should be tempered. This does not mean that animal research has never produced any or even many important medical benefits, but these claims require empirical validation, not simply repeated assertion.

It also means that scientists and science agencies should be much more aggressive about seeking and funding alternatives to animals in research. Support has certainly grown, but investment of money and human labor into non-animal alternatives has been paltry. Even with this limited investment, some impressive advances are being made — witness the ongoing development of " organs on a chip " — but much more needs to be done, with more money behind it, and with more of a sense of haste.

Beyond funding, the scientific community simply needs to adopt a better attitude toward innovation in alternatives, or else their limitations will continue to be a self-fulfilling prophecy. This is science — a discipline with a remarkable history of achievement and innovation despite significant technical challenges. Where are the editorials galvanizing the scientific community to continue to innovate without animals? Where is the Human Genome Project-type investment in alternatives? To say that animal models are "necessary" when alternatives are not aggressively pursued seems a bit dishonest. And given the amount of harm caused to animals in research—whether you think it's justified or not—we should all want the alternatives field to grow.

Literally thousands of books and peer-reviewed papers have been written on the extent of our moral obligations to animals. As a field that is dedicated to rigorous inquiry and rational thought, the scientific community should take seriously the vast philosophy literature on these topics — the same field that gave rise to the conceptual foundations of science — rather than assertions and rhetoric. When it comes to animals and ethics, there have been very few serious attempts to engage the intellectual issues. Scientists can and should do better.

Samual Garner is a bioethicist living in Washington, DC. He is an associate fellow at the Oxford Centre for Animal Ethics and writes on human research ethics and animal ethics.

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Arguments against animal testing

Animal experiments are cruel, unreliable, and even dangerous

The harmful use of animals in experiments is not only cruel but also often ineffective. Animals do not naturally get many of the diseases that humans do, such as major types of heart disease, many types of cancer, HIV, Parkinson’s disease or schizophrenia. Instead, signs of these diseases are artificially induced in animals in laboratories in an attempt to mimic the human disease. Yet, such experiments belittle the complexity of human conditions which are affected by wide-ranging variables such as genetics, socio-economic factors, deeply-rooted psychological issues and different personal experiences.

It is not surprising to find that treatments showing “promise” in animals rarely work in humans.  Not only are time, money and animals’ lives being wasted (with a huge amount of suffering), but effective treatments are being mistakenly discarded and harmful treatments are getting through. The support for animal testing is based largely on anecdote and is not backed up, we believe, by the scientific evidence that is out there.

Despite many decades of studying cancer, Alzheimer’s disease, Parkinson’s disease, diabetes, stroke and AIDS in animals, none of these conditions have reliable and fully effective cures and some don’t even have effective treatments.

The history of cancer research has been the history of curing cancer in the mouse. We have cured mice of cancer for decades and it simply didn’t work in human beings.

Unreliable animal testing

• 92% of drugs fail in human clinical trials despite appearing safe and effective in animal tests, often on safety grounds or because they do not work.
• Urology drugs have the lowest success rate (only 4% are approved after entering clinical trials) followed by heart drugs (5% success rate), cancer drugs (5% success rate) and neurology drugs (6% success rate).
• Our research has shown that using dogs, rats, mice and rabbits to test whether or not a drug will be safe for humans provides statistically little useful insight. Our study also revealed that drug tests on monkeys are just as poor as those using any other species in predicting the effects on humans.
• A recent study found that out of 93 dangerous drug side effects, only 19% could have been predicted by animal tests.
• Another study showed that over 1,000 potential stroke treatments have been “successful” in animal tests, but of the approximately 10% that progressed to human trials, none worked sufficiently well in humans.
• One review of 101 high impact discoveries based on basic animal experiments found that only 5% resulted in approved treatments within 20 years. More recently, we conducted an analysis of 27 key animal-based ‘breakthroughs ’ that had been reported by the UK press 25 years earlier. Mirroring the earlier study, we found only one of the 27 “breakthroughs” had been realised in humans, and that was subject to several caveats.

Dangerous animal testing

• Vioxx, a drug used to treat arthritis, was found to be safe when tested in monkeys (and five other animal species) but has been estimated to have caused around 140,000 heart attacks and strokes and 60,000 deaths worldwide.
• Human volunteers testing a new monoclonal antibody treatment (TGN1412) at Northwick Park Hospital, UK, in 2006 suffered a severe immune reaction and nearly died. Testing on monkeys at 500 times the dose given to the volunteers totally failed to predict the dangerous side effects.
• A drug trial in France resulted in the death of one volunteer and left four others severely brain damaged in 2016. The drug, which was intended to treat a wide range of conditions including anxiety and Parkinson’s disease, was tested in four different species of animals (mice, rats, dogs and monkeys) before being given to humans.
• A clinical trial of Hepatitis B drug fialuridine had to be stopped because it caused severe liver damage in seven patients, five of whom died. It had been tested on animals first.

Animals are different

• Animals do not get many of the diseases we do, such as Parkinson’s disease, major types of heart disease, many types of cancer, Alzheimer’s disease, HIV or schizophrenia.
• An analysis of over 100 mouse cell types found that only 50% of the DNA responsible for regulating genes in mice could be matched with human DNA.
• The most commonly used species of monkey to test drug safety (Cynomolgous macaque monkeys) is resistant to doses of paracetamol (acetaminophen) that would be deadly in humans.
• Chocolate, grapes, raisins, avocados and macadamia nuts are harmless in humans but toxic to dogs.
• Aspirin is toxic to many animals and would not be on our pharmacy shelves if it had been tested according to current animal testing standards.

The science relating to animal experiments can be extremely complicated and views often differ. What appears on this website represents Cruelty Free International expert opinion, based on a thorough assessment of the evidence.

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Millions of animals are used and killed in the name of progress every year.

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Peter Singer: Are experiments on animals ethically justifiable?

Petra Stock

Professor Peter Singer does not take an absolutist position on the ethics of using animals in scientific research. 

The world-renowned ethicist and philosopher, based at Princeton University in the US, has been revisiting the issue of experimentation on animals, in updating and republishing his most famous book –  Animal Liberation Now – after more than 40 years.

In the book, Singer writes: “it will not do to say ‘Never!’” when it comes to scientific and medical research. 

In conversation with  Cosmos ,   Singer clarifies. He says there may be examples of lifesaving research, where even after giving full weight to the interests of animals, the research might still be justified by the very large number of people who will benefit, if it comes off – if there are genuinely no alternatives. 

“But I think it’s quite rare, and I don’t think the system that we have of assessing experiments is really rigorous enough to allow only those sorts of experiments to pass.”

Much of the research on animals today is not about developing life-saving drugs, he says. A lot of the substances being tested are not essential. They might be a new sunscreen or cleaning agent, or a rival pharmaceutical company working on an alternative to a tried-and-tested medicine in order to gain a slice of that lucrative market.

“A very substantial proportion of the research that is done on animals, is not for urgent, lifesaving conditions, and would not be justified if we were to consider the interests of the animals in a serious and significant way, as I think we should,” he says.

It continues to take place, he says, “because the animals become tools for research. The experimenter has no problem ordering another batch of a couple of 100 mice to do research on. I think that’s the problem.”

Significant numbers of animals are used in scientific and medical research in Australia and other countries. Based on available data, Singer’s book estimates as many as 15.6 million animals are experimented on in the US, and more than 52 million in China. 

“A very substantial proportion of the research that is done on animals, is not for urgent, lifesaving conditions, and would not be justified if we were to consider the interests of the animals in a serious and significant way, as I think we should.” Peter Singer

As  Cosmos  has previously reported , some 700,000 mice and 30,000 rats are used in research in Australia based on statistics from 3 states. Advocates say the national figure is likely in excess of 1 million rodents, in addition to other laboratory animals. 

In Australia, all research involving animals is required to seek approval through Animal Ethics Committees and must consider the “3Rs” of replacement, reduction and refinement.

Singer says he has previously served on an animal ethics committee at Monash University. He believes that while there is some value in the process, it doesn’t go far enough.

As world shifts to non-animal testing CSIRO outlines opportunities for Australia

“Too often the majority of the committee are scientists already trained and set in that way of doing research,” he says.

That makes it hard for researchers to see the alternatives, even though that could potentially lead to better scientific outcomes.

In his book, Singer highlights problems relating to the transferability of animal research. He quotes Richard Klausner, a former director of the US National Cancer Institute as saying: “We have cured mice of cancer for decades and it simply didn’t work in humans”.

Speaking with  Cosmos , Singer mentions a presentation from the 12 th  World Congress on Alternatives and Animal Use in the Life Sciences, an event at which he delivered the closing address.

Researchers in Canada tested substances on laboratory mice housed in two different set ups. One group of mice were kept in the standard way, in small containers the size of a shoebox, with a grid on top and bright lights, which he describes as “quite stressful conditions for mice”.

Meanwhile another group of mice were housed in quarters more suitable to their nature, with places they could hide, and tunnels to run through.

“The basic question is, are these animals who can suffer?” Peter Singer

Singer says, the researchers found when they tested substances on two groups, they got quite different reactions depending on the conditions the mice were kept in. 

This raises questions about the veracity of experimental results involving animals like mice, already stressed by the laboratory environment and practices.

Do mice and rats deserve greater ethical consideration in science? 

“The basic question is, are these animals who can suffer?,” Singer replies.

He says there’s no doubt that mice and rats – which represent the majority of laboratory animals used in science and research – can suffer. They’re mammals, vertebrates, with the same basic nervous system and brains like humans, albeit significantly smaller.

“In some respects, because they don’t understand this situation, things may be more terrifying to them than they would be to us,” he says.

“I certainly think that they count.”

Originally published by Cosmos as Peter Singer: Are experiments on animals ethically justifiable?

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Can we ethically justify harming animals for research?

Lecturer in Bioethics, Monash University & Honorary fellow, Melbourne Law School, Monash University

Disclosure statement

Julian Koplin receives funding from Ferring Pharmaceuticals.

Monash University provides funding as a founding partner of The Conversation AU.

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Neuralink, the biotechnology company co-founded by Elon Musk, has been accused of animal cruelty and is under federal investigation in the United States for potential animal welfare violations.

The company has tested its brain-implant technology in animals including monkeys, sheep and pigs. Whistleblowers allege it has killed about 1,500 animals since 2018.

They claim testing was rushed , which caused significant animal suffering and required botched experiments to be repeated – harming more animals than necessary.

This scandal highlights an old but important question: when is it acceptable to harm non-human animals for human ends?

Read more: Neuralink's monkey can play Pong with its mind. Imagine what humans could do with the same technology

Moral confusion

The condemnation of Neuralink suggests many people view animal suffering as a serious moral problem. We find similar attitudes when people are outraged by pet owners neglecting or abusing their pets.

But our responses to animal suffering are complicated. Surveys show many people think at least some forms of animal research are ethically acceptable, such as medical research where alternatives aren’t available. Most people also think it is not morally evil to buy a hamburger, animal welfare concerns aside.

Our attitudes towards animals are confusing – and arguably self-serving . We need to think more carefully about how animals ought to be treated.

Do animals matter?

In the 17th century, philosopher René Descartes famously described animals as mere “automata”. He believed they lack a soul and a mind, and are therefore incapable of suffering.

But progress in fields such as ethology and the cognitive sciences has improved our understanding of animal behaviour, and we have come to appreciate animals have rich mental lives. There is now scientific consensus that mammals, birds and many others are capable of feeling pain and pleasure.

One might argue that, even if animals can suffer, ethics should only concern how we treat fellow humans since animals are not “one of us”. But this view is unsatisfying.

If somebody were to say it doesn’t matter how we treat people with a different skin colour, because they are not “one of us”, we would (rightly) call them racist. Those who claim the same about animals can be accused of making a similar mistake .

Our treatment of animals has come under increasing philosophical scrutiny since the time of Descartes. Some of the most powerful challenges have come from utilitarian philosophers such as Jeremy Bentham (1748-1832) and Peter Singer, whose 1975 book Animal Liberation was a rallying point for critics of livestock farming and animal research.

But the case for animal welfare isn’t just utilitarian. Thinkers from diverse philosophical traditions share this position.

Philosophical views on animal welfare

Philosophers usually think about animal suffering in accordance with one of three moral theories: utilitarianism, deontology and virtue ethics.

Utilitarians believe we should do what best promotes the overall wellbeing of everybody affected by a choice. They typically hold that all suffering matters equally, regardless of who experiences it, or even what species they belong to.

In 1789, Bentham argued that when it comes to animal welfare:

[…] the question is not, can they reason? Nor, can they talk? But can they suffer?

Deontologists emphasise duties and rights over welfare. They maintain we are not morally permitted to violate rights, even when doing so would promote overall wellbeing.

The great deontologist philosopher Immanuel Kant held that humans have rights because of our rationality (which more or less refers to our abilities to reason and make moral decisions). Kant believed animals aren’t rational and therefore don’t have rights (although he claimed we should still refrain from mistreating them since, according to him, that might make us more likely to mistreat humans).

Kant’s rejection of animal rights faces two challenges. First, some argue certain intelligent species, such as elephants and chimpanzees , are also rational and hence deserve rights.

Second, many contemporary deontologists argue we should set a less demanding threshold for moral rights. Rather than requiring rationality, they suggest it might be enough for an animal to have desires and interests.

Virtue ethicists take yet another approach. They think morality is a matter of developing and practising good character traits, such as honesty and compassion, while avoiding traits like dishonesty and cowardice. Virtue ethicists who deal with animal ethics have argued animal experimentation displays and reinforces vices like callousness and cruelty, particularly when research is unlikely to achieve morally important goals.

Neuralink revisited

In Australia and the United States, animal research is governed largely by the “ three Rs ”: directives to replace animal research with other strategies when feasible, reduce the number of animals used as much as possible, and refine experimental techniques to minimise animal pain.

If the reports about Neuralink are correct, the company failed to adhere to these. But what if Neuralink had conducted experiments in line with the three Rs – would this have resolved all ethical concerns?

Probably not. The three Rs are silent on one crucial question: whether the scientific gains from a particular study are great enough to justify the harms that research may inflict.

So long as an experiment is scientifically sound, one could, in principle, follow the three Rs to the letter while still inflicting severe suffering on a great many animals, and with little prospect of benefiting humans. If animals have moral worth, as the utilitarian, deontological and virtue ethical views state, then at least some scientifically sound animal research should not be conducted.

Neuralink has admirable goals, which include curing paralysis, blindness and depression.

But utilitarians might question whether the expected benefits are great enough (or likely enough ) to outweigh the significant harms to animals. Deontologists might question whether any of the species used have moral rights against being experimented on, particularly intelligent ones such as monkeys and pigs. And virtue ethicists might worry the testing performed involves vices such as callousness.

Where are we headed?

Animal research is widely practised in Australia, with more than 6 million animals reportedly used per year. Some (but not all) of this research involves significant pain and suffering. Mice are the most common animal used, though species such as dogs, cats and non-human primates are also used.

The vast number of lives at stake mean it is imperative to get the ethics right.

This means developing a more comprehensive set of principles for animal research than the three Rs: one that will help us more effectively balance scientific benefit against harms to research animals. At least among philosophers, this work is already under way .

It might also involve revisiting the question of when (if ever) certain species should be used in research. Australia imposes special restrictions on the use of non-human primates. Other jurisdictions have banned or considered banning ape research . What other intelligent species ought to receive additional protections?

We need to look beyond the three Rs for a full assessment of the ethics of animal research – both for Neuralink and beyond.

Read more: What is ethical animal research? A scientist and veterinarian explain

• Utilitarianism
• Research ethics
• Animal testing
• Animal research
• Animal ethics
• Ethical issues

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Ethics of Medical Research with Animals

U.S. Law and Animal Experimentation: A Critical Primer

Every country’s law permits medical experimentation on animals. While some countries protect particular kinds of animals from being subject to experimentation—notably great apes and endangered species—very few place concrete limitations on what researchers may cause animals to suffer, given sufficient scientific justification. What laws do, instead, is establish standards for the humane treatment and housing of animals in labs, and they encourage researchers to limit or seek alternatives to the use of animals, when doing that is consistent with the scientific goals of their research. The result, of course, is that no existing regulatory scheme is satisfactory to opponents of animal research. The law, in their view, does nothing more than make the animal research scientist into a sort of James Bond villain: superficially polite, offering fine housing and well-prepared cuisine even to those whom he intends, eventually, to kill.

Of course, the goals of animal experimentation law seem much more reasonable if one accepts that research on animals is both important for medical progress and morally permissible. On those assumptions, it makes a great deal of sense for the law to aim primarily at limiting unnecessary animal suffering even as it licenses scientifically justified experimentation. U.S. law accepts those assumptions and adopts that aim.

The system that has evolved in the United States combines elements of sometimes competing regulatory philosophies. The result is a complex, multilayered system that addresses the most important concerns, but, partly because of historical accident, also leaves some gaps. Even proponents of medical research on animals can see obvious ways in which the regulatory structure could be changed to benefit animals. Perhaps more important, though, is the fact that the existing regulatory structure, imperfect though it may be, is elastic enough to accommodate substantial changes that could reduce unnecessary animal suffering.

Multiple Regulatory Approaches

Animal welfare laws must address three main ways in which unnecessary animal suffering can occur in the context of medical experimentation. First, such suffering can occur when a given research protocol is not well justified scientifically. An experiment that was so badly designed that it could never generate any useful scientific knowledge would never warrant animal suffering. Harder cases result when the amount of suffering is ratcheted down, or the experiment’s potential to generate useful knowledge is ratcheted up. A legal regime concerned with avoiding this kind of unnecessary suffering can opt to trust in the judgment of each individual research scientist, or empower someone besides the researcher to make at least some baseline assessment of the scientific value of each new animal research protocol. It can also provide information and guidance to researchers or overseers to improve their decisions.

Second, unnecessary suffering can occur when the amount of animal suffering induced by an experiment is not strictly required to conduct the experiment—perhaps because more animals are used than are necessary; or because less sentient animals could be substituted for more sentient ones, or computer or tissue models substituted for animals entirely; or because crude experimental procedures are producing avoidable stress or pain. A legal framework seeking to avoid these kinds of unnecessary suffering will encourage or require researchers to use the three Rs: reduce (the number of animals used in experiments), replace (animals with nonanimals, higher-order animals with lower), and refine (experimental procedures causing pain or distress). [1]

Third, unnecessary suffering can occur outside the actual research protocol yet still in the research setting because of inappropriate animal handling, housing, and feeding practices. A legal regime seeking to avoid this kind of suffering will dictate humane standards for animal housing and care.

Given these goals, what sort of regulatory scheme would be best at realizing them? One can imagine a variety of available approaches, from strong, centralized state regulation and monitoring of all experimentation to a hands-off reliance on professional self-regulation among laboratory researchers. On the world stage, the United Kingdom is closest to taking the former approach, Japan to the latter. U.S. law falls somewhere in the middle, in part because U.S. law in this area is in fact the result of a gradual, decades-long merging of the government regulatory and professional self-regulatory approaches. [2]

The government regulatory approach is embodied in the sprawling, strange, and often amended Animal Welfare Act of 1966. In its original form, the AWA was designed to control pet breeding and sale practices; it was passed, in part, as a result of public outcry about the mistreatment of dogs sold to laboratories. As amended, it governs the treatment of animals in a wide range of settings, from pet shops to circuses and from zoos to laboratories. Its enforcement is delegated to the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service, whose inspectors make unannounced site visits to research facilities. Violations uncovered on such visits can result in fines and even, in extreme cases, criminal prosecution. The most common complaint about enforcement under the AWA is that it is rigid and mechanistic.

Because of its historical roots in concern for pets, the AWA’s reach is confined to warm-blooded animals, and it contains special regulations addressed to certain animal favorites: dogs, cats, rabbits, and monkeys. Its animal experimentation regulations apply to any school or research facility that purchases or transports live animals in interstate commerce or that receives federal funding. But in fact the law has never reached the bulk of warm-blooded animals actually used in research. Concern about high regulatory costs—and about possible delay in creating guidelines for other, more popular animals—led the USDA to exclude laboratory rats and mice from its oversight from as early as 1970. In spite of lobbying efforts in the 1980s by proanimal groups, a congressional amendment to the AWA in 2002 legally formalized the agency’s longtime practice, excluding rats, mice, and birds from the definition of “animal.” [3]

In general, the law and its implementing regulations have focused on setting demanding, detailed standards for animal housing and basic standards for pain control. It supports only minimal review of the scientific merit of research protocols, but it requires researchers to make efforts to “reduce, replace, and refine.”

The self-regulatory approach to animal research regulation is embodied in the National Institutes of Health’s Guide for the Care and Use of Laboratory Animals . [4]   The Guide has existed in some version since 1963, when it was introduced as a voluntary set of professional standards for laboratory animal research. Today, the Guide’s standards are mandatory for all research facilities receiving federal funds. The Guide covers the treatment of all vertebrates, which means that, at least in federally funded research, it closes many of the gaps left open by the AWA. Not only are rats, mice, and birds covered, but also cold-blooded vertebrates like zebra fish—currently the go-to animal for laboratory studies of pain and nerve function.

The change in the Guide’s status to a rulebook has altered its content somewhat. Earlier editions’ expansive aspirational goals have given way in later editions to more readily applicable rules. There has also been considerable pressure to get the AWA’s regulatory requirements and the Guide’s standards to match, since all federally funded researchers are bound by both. Indeed, today, the two sets of standards are, if not identical, at least compatible with one another. But in general, where the AWA regulations are more rigidly prescriptive, the Guide permits lab veterinarians to use their professional judgment in applying general standards to particular species or protocols.

Clearly there is room for reform. If the AWA were amended to include rats, mice, and birds, for example, that would be a major step toward ensuring the humane treatment of all animals in public and private labs.  

Federal standards are full of specific requirements for different kinds of studies, but in general, it is fair to say that they offer the most concrete guidance on questions of animal housing and care. The regulations include detailed discussions of square footage, exercise requirements, room temperature, and more. Considerably less guidance is offered on issues of protocol evaluation and implementation of the three Rs.

Of course, this is exactly what might be expected given the incredible volume and variety of animal research in the United States. A central authority can say a lot about how to house and feed monkeys, mice, and zebra fish, and expert advice on those issues will apply to all monkeys, mice, and zebra fish in every lab, no matter what protocols they are being used for. But questions about the other possible sources of unnecessary animal suffering—the scientific justification of a given protocol, or the ways in which animal suffering connected to a given protocol might be avoided or reduced—are too numerous and varied to be answerable in advance by a central authority. With regard to those highly fact-specific questions, U.S. law relies on the expert judgment of local IACUCs.

It is no coincidence that this kind of reliance on decentralized expert committees is also the salient feature of U.S. law governing research on human subjects. The federal Common Rule, [5]  faced with a similar diversity of research protocols to evaluate, regulate, and modify, uses the same tactics as the AWA: it mandates creating research oversight committees (institutional review boards), specifies that their membership should include both relevant expertise and community representation, and empowers them to make and enforce a range of judgments about particular experimental protocols.

While the many IACUCs are expected to exercise independent judgment with regard to the scientific issues brought before them, the U.S. government does its best to inform the judgment by providing them with educational resources. The Public Health Service and the Department of Agriculture Web sites are full of guidance documents and educational resources for laboratory researchers and for IACUC members. There are documents, for example, with specific ideas about how and when to substitute lower-order animals for higher-order animals, and other documents providing up-to-date scientific news about newly developed computer models that can substitute, in some cases, for animal experimentation.

Finally, just as in the human subjects research world, federal regulations are quite commonly supplemented by private education and accreditation. Many research facilities seek accreditation by the Association for the Assessment and Accreditation of Laboratory Animal Care, a professional association of veterinarians and laboratory scientists. AAALAC provides education and does prearranged site inspections of labs once every three years. Educational and inspection standards are built largely around the requirements of the Guide , and the NIH accepts AAALAC accreditation as prima facie evidence of a facility’s compliance with the Guide’s requirements.

Toward Reform: Accountability, Uniformity, Balance

The system of decentralized oversight by local IACUCs has several obvious advantages: it permits oversight by people with knowledge of the local researchers and laboratory facilities; it allows IACUCs to develop specialized knowledge, well tailored to the research being done at their facilities; and it is likely more speedy than any alternative program of centralized governmental research oversight would be. On the other hand, the decentralization of oversight has given rise to a number of problems—which, not surprisingly, are similar to those that beset the IRB system in human subjects research.

First, there is a problem of transparency and accountability. IACUCs are for the most part fairly anonymous. Hardly anyone not directly involved in animal research knows that they exist, much less who their members are. And of course, their members are not elected or in any other way publicly accountable for the decisions they make. Most IACUC decisions do not take the form of opinions or any other form of substantive, publishable decision, but of recommendations to researchers for piecemeal alteration of protocols. A central repository of IACUC minutes, and of policies adopted by different IACUCs, might both increase accountability and stimulate new ideas by creating cross talk between IACUCs. But any such repository would have to be created with an eye toward preserving researchers’ intellectual property.

Second, decentralization almost necessarily gives rise to a lack of uniformity in decision-making and in quality of research oversight. One IACUC may conclude that a protocol involves unnecessarily harsh treatment of animals or presents an opportunity for substitution of nonanimal models; another may view the original protocol as unproblematic and requiring no amendment. A number of studies have shown that similar protocols are treated quite differently by different IACUCs. [6]  It is unclear what the implications of such findings are. Do they reveal that IACUCs have differing standards relating to animal welfare? That they judge similar protocols differently when they are presented by different researchers? Or some combination of these factors? In any case, enforced uniformity across IACUCs is a dangerous solution to propose for the problem of varying standards, in the absence of clear knowledge about whose standards are appropriate—and whose would be enforced.

A third complaint about the decentralized approach to animal-research regulation involves the perception that the U.S. government is too deferential to local IACUCs and does not take the task of auditing labs sufficiently seriously. In the early 2000s, there were some high-profile allegations made by whistleblowers from the USDA’s Animal and Plant Health Inspection Service (APHIS) that audit findings were deliberately being watered down to be less critical than the field officers originally intended them to be. [7]  U.S. audits of APHIS confirmed allegations of lax auditing in some regions of the country. [8]  The obvious reform here is to better fund and train both the regulatory overseers and those who audit their performance.

There are other important criticisms of the U.S. regulatory regime not directly connected to its choice of decentralized decision-making. First, there is the question of scientific justification for animal suffering. The AWA does not ask IACUCs to balance animal suffering against the scientific merit or promise of any given experiment. Instead, it asks IACUCs to ensure only that any given protocol has scientific merit and that any animal suffering the protocol induces is strictly necessary to that science. The result is that any study that will advance science, even in a very small way, can be used to justify tremendous amounts of animal suffering, as long as the suffering is necessary to the advance. Though they do seek to modify studies via use of the three Rs, IACUCs almost never reject protocols.

Finally, and most importantly, there is the issue of which animals are protected. As already mentioned, the hundreds of thousands of rats, mice, and birds used in private, nonfederally funded labs are not subject to any federal regulation. (Some individual states’ anticruelty statutes may apply in some cases, but there is very limited case law in the area.) Excluded, also, are cold-blooded animals. This means that there is no federal legal pressure on private firms such as drug companies to reduce or refine animal use, or to replace animals with computer or tissue models—a strategy that may be particularly feasible in studies of toxicology or drug metabolization.

Even in federally funded facilities, the living conditions of rats, mice, and birds are not subject to the USDA’s APHIS inspection; only in AAALAC-accredited facilities is there oversight beyond self-reporting, and AAALAC does scheduled inspections only once every three years. Rats and mice, it should be stressed, are the most commonly used laboratory animals. In addition, U.S. law offers no protection for invertebrate, cold-blooded animals such as cephalopods. By contrast, Europe has recently moved to protect cephalopods in light of their manifest intelligence and sentience. Nor does U.S. law prevent research on great apes, or ban (though it does regulate) the use of wild-caught animals. And the United States is one of only two governments in the world that still permits invasive research on chimpanzees, though the scope of federal funding for chimp research has recently been sharply limited. [9]  (See “Raising the Bar: The Implications of the IOM Report on the Use of Chimpanzees in Research,” in this volume.)

Clearly there is room for reform. Some needed reform involves stepping up research oversight. If the AWA were amended to include rats, mice, and birds, for example, that would be a major step toward ensuring the humane treatment of all animals in public and private labs. In addition, the inspection rate for facilities could be more frequent. Publicly funded U.S. labs are inspected by APHIS about once a year, by their own IACUCs twice a year, and by AAALAC (if they choose to be AAALAC-certified) once every three years. Compare this to the U.K. system of inspecting about once a month. Other reforms could involve improving rigid and not-terribly-useful existing regulations, like cage-size requirements currently based on animals’ body size rather than on their behavioral needs. Most significantly, the law could be reformed to permit a more explicit balancing of harms to animals (including both suffering and death) against the scientific gains at which the research aims. Empowering IACUCs to engage in such balancing is hardly radical; IRBs, for example, are already empowered to engage in such balancing in the human subjects research area, and this has not caused research to grind to a halt. Such a reform would require us to confront directly the question of how much suffering humans can impose on other species in return for small but real gains in knowledge.

Finally, a great deal can be accomplished even within an unchanged legal regime. The most urgent need is for more to be done to implement the three Rs. The familiar calls for better education about replacement techniques and more aggressive IACUC intervention on behalf of reduction and refinement are, of course, well justified. But even more dramatic reduction might be achieved if the goal of reduction were pursued not only within but also across protocols. There might be significant gains from putting animal-sharing procedures in place at the institutional level. At the moment, animals are commonly euthanized whenever the particular research project they’re involved in comes to an end, without regard to the animal’s age or health status. If a protocol involves attempts to breed, for example, mice with particular genetic traits, the pups born without those traits are routinely euthanized. If research facilities could work with researchers to use healthy animals from one study in another, rather than default to their euthanization, then fewer animals would need to be bred for suffering.

Stephen R. Latham is director of the Interdisciplinary Center for Bioethics at Yale University. He has published on a broad range of issues at the intersection of bioethics and law. He is a former board member of the American Society for Bioethics and Humanities, a former graduate fellow of Harvard’s Safra Center on Ethics, and a former research fellow of the University of Edinburgh’s Institute for Advanced Studies in Humanities. His current research includes a project funded by the Robert Wood Johnson Foundation to create a database of state statutes and cases criminalizing HIV exposure and a project on a legal framework for newborn whole-exome screening. 

• 1. The widely accepted “Three Rs” terminology was first introduced into the animal research literature in W.M.S. Russell and R.L. Burch, The Principals of Human Experimentation Technique (London: Methuen, 1959). ↵
• 2. A detailed account of the confluence of these two streams of regulation (to which my brief discussion here is heavily indebted) is provided by L. Carbone, What Animals Want: Expertise and Advocacy in Laboratory Animal Welfare Policy (Oxford, U.K.: Oxford University Press, 2004), p. 34ff. ↵
• 3. Wild-caught rats and mice are included in the regulations. For more detail, see Carbone, What Animals Want , p. 69ff. ↵
• 4. National Research Council, Guide for the Care and Use of Laboratory Animals , 8th ed.(Washington, D.C.: National Academies Press, 2011). ↵
• 5. U.S. Department of Health and Human Services, 45 CFR 46. ↵
• 6. See, for example, S. Plous and H. Herzog, “Reliability of Protocol Reviews for Animals Research,” Science 293 (2001): 608-9. ↵
• 7. See, for example, the statement of Dr. Isis Johnson-Brown, USDA whistleblower, alleging regulatory inaction on her report criticizing cage conditions at the Oregon Primate Center, at http://www.all-creatures.org/saen/articles-statementofijb.html, accessed October 2, 2012. ↵
• 8. USDA Office of Inspector General, Western Region, “Audit Report: APHIS Animal Care Program Inspection and Enforcement Activities,” Report No. 33002-3-SF, September 2005, p. i, http://www.usda.gov/oig/webdocs/33002-03-SF.pdf. ↵
• 9. See Institute of Medicine, Committee on the Use of Chimpanzees in Biomedical and Behavioral Research: Assessing the Necessity (Washington, D.C.: National Academies Press, 2011); B.M. Altevogt et al., “Guiding Limited Use of Chimpanzees in Research,” Science 335 (2012): 41-42. ↵

Should Animals Be Used for Scientific or Commercial Testing?

• History of Animal Testing

Animals are used to develop medical treatments, determine the toxicity of medications, check the safety of products destined for human use, and other  biomedical , commercial, and health care uses. Research on living animals has been practiced since at least 500 BC.

Descriptions of the dissection of live animals have been found in ancient Greek writings from as early as circa 500 BC. Physician-scientists such as  Aristotle ,  Herophilus , and  Erasistratus  performed the experiments to discover the functions of living organisms.  Vivisection  (dissection of a living organism) was practiced on human criminals in ancient Rome and Alexandria, but prohibitions against mutilation of the human body in ancient Greece led to a reliance on animal subjects. Aristotle believed that animals lacked intelligence, and so the notions of justice and injustice did not apply to them.  Theophrastus , a successor to Aristotle, disagreed, objecting to the vivisection of animals on the grounds that, like humans, they can feel pain, and causing pain to animals was an affront to the gods. Read more background…

Pro & Con Arguments

Pro 1 Animal testing contributes to life-saving cures and treatments for humans and animals alike. Nearly every medical breakthrough in the last 100 years has resulted directly from research using animals, according to the California Biomedical Research Association. To name just a few examples, animal research has contributed to major advances in treating conditions including breast cancer, brain injury, childhood leukemia, cystic fibrosis, multiple sclerosis, and tuberculosis. Testing on animals was also instrumental in the development of pacemakers, cardiac valve substitutes, and anesthetics. [ 9 ] [ 10 ] [ 11 ] [ 12 ] [ 13 ] Scientists racing to develop a vaccine for coronavirus during the 2020 global pandemic needed to test on genetically modified mice to ensure that the vaccine did not make the virus worse. Nikolai Petrovsky, professor in the College of Medicine and Public Health at Flinders University in Australia, said testing a coronavirus vaccine on animals is “absolutely essential” and skipping that step would be “fraught with difficulty and danger.” [ 119 ] [ 133 ] Researchers have to test extensively to prevent “vaccine enhancement,” a situation in which a vaccine actually makes the disease worse in some people. “The way you reduce that risk is first you show it does not occur in laboratory animals,” explains Peter Hotez, Dean for the National School of Tropical Medicine at Baylor College. [ 119 ] [ 141 ] Further, animals themselves benefit from the results of animal testing. Vaccines tested on animals have saved millions of animals that would otherwise have died from rabies, distemper, feline leukemia, infectious hepatitis virus, tetanus, anthrax, and canine parvo virus. Treatments for animals developed using animal testing also include pacemakers for heart disease and remedies for glaucoma and hip dysplasia. [ 9 ] [ 21 ] Animal testing has also been instrumental in saving endangered species from extinction, including the black-footed ferret, the California condor and the tamarins of Brazil. The American Veterinary Medical Association (AVMA) endorses animal testing to develop safe drugs, vaccines, and medical devices. [ 9 ] [ 13 ] [ 23 ] Read More

Pro 2 Animals are appropriate research subjects because they are similar to human beings in many ways. Chimpanzees share 99% of their DNA with humans, and mice are 98% genetically similar to humans. All mammals, including humans, are descended from common ancestors, and all have the same set of organs (heart, kidneys, lungs, etc.) that function in essentially the same way with the help of a bloodstream and central nervous system. Because animals and humans are so biologically similar, they are susceptible to many of the same conditions and illnesses, including heart disease, cancer, and diabetes. [ 9 ] [ 17 ] [ 18 ] Animals often make better research subjects than humans because of their shorter life cycles. Laboratory mice, for example, live for only two to three years, so researchers can study the effects of treatments or genetic manipulation over a whole lifespan, or across several generations, which would be infeasible using human subjects. Mice and rats are particularly well-suited to long-term cancer research, partly because of their short lifespans. [ 9 ] [ 29 ] [ 30 ] Further, animals must be used in cases when ethical considerations prevent the use of human subjects. When testing medicines for potential toxicity, the lives of human volunteers should not be put in danger unnecessarily. It would be unethical to perform invasive experimental procedures on human beings before the methods have been tested on animals, and some experiments involve genetic manipulation that would be unacceptable to impose on human subjects before animal testing. The World Medical Association Declaration of Helsinki states that human trials should be preceded by tests on animals. [ 19 ] [ 20 ] A poll of 3,748 scientists by the Pew Research Center found that 89% favored the use of animals in scientific research. The American Cancer Society, American Physiological Society, National Association for Biomedical Research, American Heart Association, and the Society of Toxicology all advocate the use of animals in scientific research. [ 36 ] [ 37 ] [ 38 ] [ 39 ] [ 40 ] [ 120 ] Read More

Pro 3 Animal research is highly regulated, with laws in place to protect animals from mistreatment. In addition to local and state laws and guidelines, animal research has been regulated by the federal Animal Welfare Act (AWA) since 1966. As well as stipulating minimum housing standards for research animals (enclosure size, temperature, access to clean food and water, and others), the AWA also requires regular inspections by veterinarians. [ 3 ] All proposals to use animals for research must be approved by an Institutional Animal Care and Use Committee (IACUC) set up by each research facility. Most major research institutions’ programs are voluntarily reviewed for humane practices by the Association for Assessment and Accreditation of Laboratory Animal Care International (AAALAC). [ 24 ] [ 25 ] Animal researchers treat animals humanely, both for the animals’ sake and to ensure reliable test results. Research animals are cared for by veterinarians, husbandry specialists, and animal health technicians to ensure their well-being and more accurate findings. Rachel Rubino, attending veterinarian and director of the animal facility at Cold Springs Harbor Laboratory, says, “Most people who work with research animals love those animals…. We want to give them the best lives possible, treat them humanely.” At Cedars-Sinai Medical Center’s animal research facility, dogs are given exercise breaks twice daily to socialize with their caretakers and other dogs, and a “toy rotation program” provides opportunities for play. [ 28 ] [ 32 ] Read More

Con 1 Animal testing is cruel and inhumane. Animals used in experiments are commonly subjected to force feeding, food and water deprivation, the infliction of burns and other wounds to study the healing process, the infliction of pain to study its effects and remedies, and “killing by carbon dioxide asphyxiation, neck-breaking, decapitation, or other means,” according to Humane Society International. The US Department of Agriculture reported in Jan. 2020 that research facilities used over 300,000 animals in activities involving pain in just one year. [ 47 ] [ 102 ] Plus, most experiments involving animals are flawed, wasting the lives of the animal subjects. A peer-reviewed study found serious flaws in the majority of publicly funded US and UK animal studies using rodents and primates: “only 59% of the studies stated the hypothesis or objective of the study and the number and characteristics of the animals used.” A 2017 study found further flaws in animal studies, including “incorrect data interpretation, unforeseen technical issues, incorrectly constituted (or absent) control groups, selective data reporting, inadequate or varying software systems, and blatant fraud.” [ 64 ] [ 128 ] Only 5% of animals used in experiments are protected by US law. The Animal Welfare Act (AWA) does not apply to rats, mice, fish, and birds, which account for 95% of the animals used in research. The types of animals covered by the AWA account for fewer than one million animals used in research facilities each year, which leaves around 25 million other animals without protection from mistreatment. The US Department of Agriculture, which inspects facilities for AWA compliance, compiles annual statistics on animal testing but they only include data on the small percentage of animals subject to the Act. [ 1 ] [ 2 ] [ 26 ] [ 28 ] [ 135 ] Even the animals protected by the AWA are mistreated. Violations of the Animal Welfare Act at the federally funded New Iberia Research Center (NIRC) in Louisiana included maltreatment of primates who were suffering such severe psychological stress that they engaged in self-mutilation, infant primates awake and alert during painful experiments, and chimpanzees being intimidated and shot with a dart gun. [ 68 ] Read More

Con 2 Animal tests do not reliably predict results in human beings. 94% of drugs that pass animal tests fail in human clinical trials. Over 100 stroke drugs and over 85 HIV vaccines failed in humans after succeeding in animal trials. Nearly 150 clinical trials (human tests) of treatments to reduce inflammation in critically ill patients have been undertaken, and all of them failed, despite being successful in animal tests. [ 57 ] [ 58 ] [ 59 ] Drugs that pass animal tests are not necessarily safe. The 1950s sleeping pill thalidomide, which caused 10,000 babies to be born with severe deformities, was tested on animals prior to its commercial release. Later tests on pregnant mice, rats, guinea pigs, cats, and hamsters did not result in birth defects unless the drug was administered at extremely high doses. Animal tests on the arthritis drug Vioxx showed that it had a protective effect on the hearts of mice, yet the drug went on to cause more than 27,000 heart attacks and sudden cardiac deaths before being pulled from the market. [ 5 ] [ 55 ] [ 56 ] [ 109 ] [ 110 ] Plus, animal tests may mislead researchers into ignoring potential cures and treatments. Some chemicals that are ineffective on (or harmful to) animals prove valuable when used by humans. Aspirin, for example, is dangerous for some animal species. Intravenous vitamin C has shown to be effective in treating sepsis in humans, but makes no difference to mice. Fk-506 (tacrolimus), used to lower the risk of organ transplant rejection, was “almost shelved” because of animal test results, according to neurologist Aysha Akhtar. A report on Slate.com stated that a “source of human suffering may be the dozens of promising drugs that get shelved when they cause problems in animals that may not be relevant for humans.” [ 105 ] [ 106 ] [ 127 ] Read More

Con 3 Alternative testing methods now exist that can replace the need for animals. Other research methods such as in vitro testing (tests done on human cells or tissue in a petri dish) offer opportunities to reduce or replace animal testing. Technological advancements in 3D printing allow the possibility for tissue bioprinting: a French company is working to bioprint a liver that can test the toxicity of a drug. Artificial human skin, such as the commercially available products EpiDerm and ThinCert, can be made from sheets of human skin cells grown in test tubes or plastic wells and may produce more useful results than testing chemicals on animal skin. [ 15 ] [ 16 ] [ 50 ] [ 51 ] Michael Bachelor, Senior Scientist and Product Manager at biotech company MatTek, stated, “We can now create a model from human skin cells — keratinocytes — and produce normal skin or even a model that mimics a skin disease like psoriasis. Or we can use human pigment-producing cells — melanocytes — to create a pigmented skin model that is similar to human skin from different ethnicities. You can’t do that on a mouse or a rabbit.” The Environmental Protection Agency is so confident in alternatives that the agency intends to reduce chemical testing on mammals 30% by 2025 and end it altogether by 2035. [ 61 ] [ 134 ] [ 140 ] Scientists are also able to test vaccines on humans volunteers. Unlike animals used for research, humans are able to give consent to be used in testing and are a viable option when the need arises. The COVID-19 (coronavirus) global pandemic demonstrated that researchers can skip animal testing and go straight to observing how vaccines work in humans. One company working on a COVID-19 vaccine, Moderna Therapeutics, worked on developing a vaccine using new technology: instead of being based on a weakened form of the virus, it was developed using a synthetic copy of the COVID-19 genetic code. [ 142 ] [ 143 ] Read More

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• Future Perfect

What’s worse than a cruel animal experiment? A cruel and fake animal experiment.

Raising the consequences for animal testing experiments gone wrong.

by Marina Bolotnikova

Last December, in the wake of animal cruelty allegations against Elon Musk’s brain chip startup Neuralink, Vox’s Kenny Torrella wrote about a concept he called “the moral math of animal testing”: the view held by many people that trading some amount of animal suffering is worth it if it can save enough human lives by advancing medicine.

Experimentation on live animals is a divisive, morally charged subject. Slightly more than half of Americans say they oppose using animals in scientific research, according to a 2018 Pew survey, but it depends a lot on how you phrase the question and who is asking. When asked by the biomedical industry whether they support “the humane use of animals” to develop “lifesaving medicines,” many more people say they do, or aren’t sure. These gaps reflect the public’s lack of understanding of how vivisection works in general: Most people don’t know whether animal testing is humane, effective, or necessary, nor do they always know how to define those terms.

Not everyone will agree with my view of vivisection, which is that it’s unjustifiable in nearly all circumstances. But I would think most people will agree that animal experiments should have to clear an especially high bar — that they have to be truly necessary for saving human lives and irreplaceable with non-animal methods.

That is, unfortunately, not how animal testing in the US works at all. Scientists harm and kill animals for all sorts of studies that have nothing to do with saving human lives. Researchers at Oregon Health & Science University, for example, have forced prairie voles to drink alcohol to test whether it makes them cheat on their partners. A Harvard neuroscientist recently came under fire for separating caged mother monkeys from their babies and giving them surrogate stuffed animals to bond with, thus demonstrating, she wrote in a top scientific journal, that “infant/mother bonds may be triggered by soft touch.”

The worst kind of fraud

Animal experimentation is also not immune to outright fraud, a problem that’s “disturbingly common” in science, as Vox’s Kelsey Piper wrote in June. Last week, federal investigators found that William Armstead, a former professor at the University of Pennsylvania’s medical school, had faked the results of multiple federally funded studies that involved cutting open piglets’ skulls and inducing brain injuries. The studies were meant to test drugs for treating brain injuries in humans. (Armstead left the university while he was under investigation for this misconduct.)

Some of Armstead’s fabrications, which included relabeling results from past studies as new ones, appear designed to make a drug his team was studying look more effective, Ivan Oransky, co-founder of Retraction Watch — a blog that tracks retractions of scientific papers — told the Philadelphia Inquirer last week. Armstead’s team doctored 51 scientific figures across five published studies, three federal grant applications, and other documents. The faked data renders the research useless; it’s now been retracted from journals and can’t be incorporated into future work. “A bunch of pigs were subjected to some pretty terrible conditions for no reason,” Oransky told the Inquirer.

Armstead now faces a seven-year ban on conducting federally funded research, a penalty that’s relatively rare in its severity. But his case isn’t an isolated one.

Last year, a pivotal 2006 mouse study, which had been thought to shed light on the pathology of Alzheimer’s disease and shaped years of federally funded research, was credibly accused of being fraudulent and remains under investigation.

Also last year, federal officials found Deepak Kaushal, then-head of the federally funded Southwest National Primate Research Center in San Antonio, to have falsified results in a published study of a tuberculosis treatment tested on monkeys, and used those results in two NIH grant applications. Kaushal was placed under a one-year supervision period — the lightest imaginable slap on the wrist — with no lasting consequences for his ability to experiment on animals. He also, according to initial reports, got to keep his job as director of the lab. After criticism from some in the research community and animal advocates, he was later demoted from that position; it’s unclear whether he’ll be reinstated after his supervision period.

The price of suffering

All these revelations should raise alarms about how misconduct is handled in research involving animal testing. When a top primate researcher is allowed to keep experimenting on monkeys after falsifying data, it sends a message to everyone in the research community that recklessly handling animal experiments, while temporarily embarrassing, may not be that big a deal.

“The NIH tends to give anybody on their pay line the benefit of the doubt,” neuroscientist Katherine Roe, who worked at NIH for more than eight years and is now chief of PETA’s science advancement and outreach division, told me. (PETA, despite its reputation, has a top-notch team of scientists challenging unethical animal research). “The penalties for research fraud are not what they should be.”

To shift the incentive structure, we need better federal regulation that raises the cost of torturing animals for botched experiments. Right now, the consequences for misconduct in federally funded research don’t take into account whether the work involved animal testing, Roe said. Federal research regulations could be amended so that scientists found responsible for misconduct in work involving vulnerable populations, including non-human animals, be permanently barred from testing on them in future federally sponsored research, a change that’s been proposed by PETA, explained Emily Trunnell, a senior scientist for the organization.

That would be a good start. But it would require the authorities who oversee science to view the animal experiments themselves, and not just lying about their results, as morally implicated, something the research community has been loath to do because it threatens to undermine the whole endeavor of animal testing.

On a higher level, we have to start seeing it as the public’s right and duty to make democratic decisions about whether and how animals are used in scientific research, especially when our money is paying for it. Scientists are an exalted class, often allowed to self-regulate, but their expertise in a narrow subject matter shouldn’t let them overrule democratic governance of research ethics. Ethics belongs to us all. And the public expects a much higher bar than too many animal researchers currently set for themselves.

• Animal Welfare

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Is Animal Testing Ever Justified?

The E.P.A. recently said it would move away from requiring the testing of potentially harmful chemicals on animals. Do you support the decision?

By Natalie Proulx

Find all our Student Opinion questions here.

On Sept. 10, the Environmental Protection Agency said it would move away from requiring the testing of potentially harmful chemicals on animals, a decision that was hailed by animal rights groups but criticized by environmentalists and researchers who said the practice was necessary to rigorously safeguard human health.

What are your thoughts on animal testing? Do you think it is ever justified? Why or why not?

In “ E.P.A. Says It Will Drastically Reduce Animal Testing ,” Mihir Zaveri, Mariel Padilla and Jaclyn Peiser write about the decision:

The E.P.A. Administrator Andrew Wheeler said the agency plans to reduce the amount of studies that involve mammal testing by 30 percent by 2025, and to eliminate the studies entirely by 2035, though some may still be approved on a case-by-case basis. The agency said it would also invest $4.25 million in projects at four universities and a medical center that are developing alternate ways of testing chemicals that do not involve animals. “We can protect human health and the environment by using cutting-edge, ethically sound science in our decision-making that efficiently and cost-effectively evaluates potential effects without animal testing,” Mr. Wheeler said in a memo announcing the changes. The E.P.A. has for decades required testing on a variety of animals — including rats, dogs, birds and fish — to gauge their toxicity before the chemicals can be bought, sold or used in the environment.

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Beyond Anthropocentrism: The Moral and Strategic Philosophy behind Russell and Burch’s 3Rs in Animal Experimentation

• Original Research/Scholarship
• Open access
• Published: 11 September 2024
• Volume 30 , article number  44 , ( 2024 )

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• Nico Dario Müller   ORCID: orcid.org/0000-0003-0866-8235 1  

The 3Rs framework in animal experimentation– “replace, reduce, refine” – has been alleged to be expressive of anthropocentrism, the view that only humans are directly morally relevant. After all, the 3Rs safeguard animal welfare only as far as given human research objectives permit, effectively prioritizing human use interests over animal interests. This article acknowledges this prioritization, but argues that the characterization as anthropocentric is inaccurate. In fact, the 3Rs prioritize research purposes even more strongly than an ethical anthropocentrist would. Drawing on the writings of Universities Federation for Animal Welfare (UFAW) founder Charles W. Hume, who employed Russell and Burch, it is argued that the 3Rs originally arose from an animal-centered ethic which was however restricted by an organizational strategy aiming at the voluntary cooperation of animal researchers. Research purposes thus had to be accepted as given. While this explains why the 3Rs focus narrowly on humane method selection, not on encouraging animal-free question selection in the first place, it suggests that governments should (also) focus on the latter if they recognize animals as deserving protection for their own sake.

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Introduction

The 3Rs in animal experimentation– “replace, reduce, refine”– are commonly understood to be a moral principle or a scientific principle whose application is morally desirable (Hobson-West, 2009 ). But what kind of moral philosophy underpins the 3Rs, if any? Readers of the classic text on the 3Rs, The Principles of Humane Experimental Technique (Russell & Burch, 1959 ), have been perplexed by this question because the authors did not engage in any moral argumentation at all. It is clear enough that Russell and Burch considered animal distress to be of moral concern, but why they thought this and in what terms they thought about it remains obscure. Today, this obscurity still gives rise to conflicting interpretations.

An essential point of contention is whether the 3Rs rest on an anthropocentric moral perspective. Anthropocentrism is the philosophical view that humans alone matter morally for their own sake, while anything else, including animals, matters only indirectly insofar as it affects humans (Fox, 1998 ). Such views are controversial among animal ethicists because they tend not to give animals sufficient moral consideration. The question, in other words, is whether the concept of the 3Rs addresses animal welfare issues in science in a characteristically anthropocentric way. Some scholars argue that anthropocentrism is a key feature of the 3Rs, particularly because they prioritize human research interests over the interests of animals (Vorstenbosch, 2005 ; Lauwereyns, 2018 ). Footnote 1 Other commentators claim the exact opposite, that the 3Rs should be understood as non-anthropocentric given their focus on animal suffering in itself rather than any indirect effects on humans (Camenzind & Eggel, 2022 ), or that they rest on the specific non-anthropocentric approach of utilitarianism (Schuppli et al., 2004 ; Landi et al., 2015 ; Walker & Eggel, 2020 ).

Understanding the values that originally underpinned the 3Rs is still important today because these values shape how the framework operates– what questions it is built to ask and what goals it is built to achieve. The 3Rs are an intellectual and regulatory tool, and it is relevant to know whether that tool was built for a purpose other than the one we are using it for. Numerous countries today allocate significant public resources to 3Rs programs (Neuhaus et al., 2022 ). This includes jurisdictions in which animals are recognized as beings worth protecting for their own sake (see Kotzmann, 2023 ). If the 3Rs are indeed rooted in anthropocentric values, thus built to help protect animals only insofar as it serves humans, this raises concerns about whether 3Rs programs align with the values enshrined in their respective legislation. The prominent role of the 3Rs in current efforts to promote new approach methods might then need to be reconsidered.

This article makes three original contributions: First, it engages directly with the notion of anthropocentrism and sets it apart from other notions, such as disregard for animal sentience, to make it clear what it means to claim that the 3Rs are anthropocentric or that they are not. This helps to put the conflicting views of previous commentators into perspective (Camenzind & Eggel, 2022 ; Lauwereyns, 2018 ; Vorstenbosch, 2005 ) (Section “ The 3Rs and the Notion of Anthropocentrism ”).

Second, the article illuminates the original philosophical foundations of the 3Rs by drawing on the writings of C. W. Hume (Section “ The Original Moral and Strategic Commitments Underpinning the 3Rs ”). These writings contain a reasoned and coherent approach to animal ethics that is explicitly non-anthropocentric. However, Hume also strongly committed to a strategic principle of cooperating with vested interests rather than challenging them. This led to an overall program of protecting animals only within the bounds of human interests in using them. While Hume’s writings have received some limited attention (Balls, 2009 , 2013 ; Balls & Parascandola, 2019 ), the influence of his strategy on the 3Rs has not been discussed before.

Third, the article reflects critically on the lasting merit of Hume’s strategy, arguing that it lacks justification in the context of government policy and governance (Section “ The Limited Justification of Hume’s Strategy ”). This is because the principle of cooperating with rather than challenging vested interests is prudent only in positions of relative powerlessness (Section “ Conclusion ”). Overall, this article represents the first attempt to address the question directly as to whether the 3Rs are an anthropocentric framework and what critical lessons can be learned from the answer.

The 3Rs and the Notion of Anthropocentrism

Anthropocentrism is the view that all and only human beings have intrinsic value, have moral status, or matter morally for their own sake (Fox, 1998 ; see also Jaworska & Tannenbaum, 2018 ; Brennan & Lo, 2022 ). The notions of “intrinsic value,” “moral status” and “mattering” can in turn be understood in terms of moral obligations (Warren, 1997 , p. 3; Müller, 2022 , p. 32): Anthropocentrism is the view that there are moral obligations to all and only humans, not to any non-human entity.

At its root, then, anthropocentrism is a view concerning the question towards whom there exist moral obligations– whom we owe their observation and who is wronged by their violation. This should be distinguished from the question why moral obligations exist or what they prescribe. As for the “why,” an anthropocentrist can endorse a variety of theories, including but not limited to contractualist (see Carruthers, 2002 ; Abbey, 2007 ), Kantian (see Callanan & Allais, 2020 ; Müller, 2022 ), and Thomist approaches (see Scott & Coetser, 2015 ; Macdonald, 2021 ).

When it comes to the question of what moral obligations ask agents to do, an anthropocentrist can advance a variety of views, too. Kant, to name one classic, argued that the treatment of animals affects human capacities that are required for morality, specifically the capacity for sympathy, and so we owe it to ourselves to refrain from cruelty to animals (Müller, 2022 , p. 60; Regan, 2004 , Ch. 5.5). But there is some leeway for theories to disagree on what exactly this anti-cruelty duty demands– for instance, on whether it implies a duty of vegetarianism (see Egonsson, 1997 ; Denis, 2000 ; Hay, 2020 ). This shows that the “to whom,” “why,” and “what” aspects of moral obligation are not completely congruent.

Because anthropocentrism is a view specifically about the “to whom” aspect of obligations, it should not be equated with views about the “why” and “what.” Consider, for example, the view that humans can treat animals whichever way they want, or that the interests of humans should be assigned greater weight than the equivalent interests of animals. Such views are better characterized as “human chauvinism” or “speciesism” (as discussed by Hayward, 1997 ) or as the rejection of “moral status unitarianism” (see Kagan, 2019 ).

The difference between the “to whom,” “why,” and “what” aspects of obligations is not always fully appreciated in debates about the 3Rs. For example, Camenzind and Eggel argue that Russell and Burch’s focus on sentient animals is a reason to think that they were not anthropocentrists ( 2022 , p. 497). But this conflates the “what” with the “to whom.” Russell and Burch certainly did acknowledge an obligation to diminish the distress of sentient animals, but this alone does not settle to whom agents owe this obligation. It could be an obligation to the animals, to other humans, to a deity, or anything else. Other commentators have argued that Russell and Burch’s focus on diminishing distress shows that they endorsed a specific non-anthropocentric theory, namely, utilitarianism (Schuppli et al., 2004 , p. 526; Landi et al., 2015 , p. 228; Walker & Eggel, 2020 , p. 8). This conflates the “what” with the “why” because a utilitarian grounding of obligations in a value to-be-maximized is not the only option. Russell and Burch could just as well have believed that diminishing distress is a divine command or a demand of a human social contract. In short, when it comes to the question whether the 3Rs are anthropocentric, the mere fact that Russell and Burch endorsed an obligation to reduce animal distress is neither here nor there.

However, some more nuance is necessary here. The “why, what, and to whom” aspects of obligations do not completely align, but they are also not completely disconnected from each other. Assumptions in one domain put certain restrictions on what can be compellingly argued in the other domains. For example, the “why” can restrict the “to whom.” Take the example of Carruthers’s view (Carruthers, 2002 , Chap. 5), according to which obligations arise from a social contract in which only rational agents participate. This kind of contractualist grounding of obligations makes it extremely difficult to account for obligations towards animals. The straightforward conclusion is that such obligations do not exist.

Similarly entangled are the “to whom” and the “what.” For instance, if obligations exist only towards humans, then animals can only be protected indirectly by virtue of standing in some relevant relation to humans. This makes it very difficult for anthropocentric theories to explain why we should devote any moral attention to animals who do not stand in that relevant relation to us. For example, a Kantian view that argues that animals matter only insofar as they affect a human’s capacity for sympathy has trouble explaining why humans should care about animals with whose expressions of pain they do not readily sympathize, such as fish, reptiles, or rodents (Müller, 2022 , pp. 76–77).

More limitations for anthropocentric approaches arise when they combine direct obligations to humans with indirect obligations regarding animals. The problem is that the former tend to outweigh or restrict the latter. In principle, of course, animal interests do not have any independent weight at all in such theories, as they derive all their apparent weight from overlapping with human interests. For example, an animal’s interest in not suffering matters in Kant’s theory only insofar as it overlaps with the human interest in retaining one’s capacity for sympathy. But the simplest and morally most desirable way to advance the human interests at stake– say, in safeguarding sympathy– typically does not require acting in full accordance with the animals’ interests.

Take the example of the brutalization of slaughterhouse workers. Assume that unrestricted animal cruelty would give workers an increasingly cruel disposition, making them dangerous to other humans. There is a human interest in preventing this effect, protected by fairly uncontroversial obligations of beneficence or nonmaleficence. This overlaps with the animals’ interest in not being made to suffer. But at the same time, some humans have an interest in meat production, and this interest is protected by fairly uncontroversial obligations too– say, to respect the freedom of other human beings. The best solution from an anthropocentric standpoint is to tolerate all the animal suffering that is necessary for meat production and to prohibit only “excessive” violence. This illustrates how anthropocentrism, because it considers animal interests only to the extent that they overlap with human interests, tends to minimize even the indirect moral consideration it grants to animals.

However, it would be incorrect to say that anthropocentrism strictly or “lexically” prioritizes human use interests over animal interests. Lexical priority would be given if interests in exploiting animals always came first and animal interests came after. But animal interests are never considered for their own sake in anthropocentric views at all, not even after all human interests have been attended to. On the other hand, situations can arise in which animal-friendly human interests prevail over animal-harming ones. For example, the practice of holding animal fights may be prohibited because the interest in safeguarding sympathy in this case outweighs the socially marginal interest in enjoying the spectacle. Thus, although anthropocentrism only considers animal interests insofar as they overlap with human interests and those human interests are often heavily restricted by direct obligations to humans, it does not strictly give lexical priority to human interests in using animals over human interests in protecting them.

Scholars who argue that the 3Rs are anthropocentric are concerned with the preference the framework gives to research interests over animal interests. The 3Rs concept is set up in such a way that the research objective is never questioned (Tannenbaum & Bennett, 2015 , p. 123). What we are to ask ourselves, according to Russell and Burch ( 1959 ), is whether there are any alternative methods, any ways to reduce the sample size, or ways to make the experiment less harmful to the animals, all without compromising scientific quality. We are however not asked to reflect on our choice of research objectives (what objectives are worth pursuing?– see Beauchamp & DeGrazia, 2020 , p. 22) or on opportunity costs (should we better pursue another bit of knowledge that does not require harm to animals?– see Lauwereyns, 2018 , p. 109). So, in deeds if not in words, the 3Rs do treat research objectives as lexically superior to animal interests. Footnote 2

Vorstenbosch ( 2005 , p. 341) argues that the 3Rs are anthropocentric because they assume that science is justified by its benefits for humans. Animal interests can justify more humane techniques, but they never make it impermissible to pursue a specific research objective. Similarly, Lauwereyns argues that Russell and Burch “suggested that we should just concern ourselves with avoiding ‘inhumanity’ in the technique” without asking whether the research objective itself was morally justified, and that in this way, their view “always, in every single case, places humans above other animals” ( 2018 , p. 14). In sum, the argument of critics who charge Russell and Burch with anthropocentrism is that the 3Rs treat the research objective as sacrosanct, considering animal interests only within the bounds set by the research endeavor. Footnote 3

Of course, one could argue that at the time of Russell and Burch’s project, the Cruelty to Animals Act of 1876 (article 3, sect. 1) allowed experiments only “with a view to the advancement by new discovery of physiological knowledge or of knowledge which will be useful for saving or prolonging life or alleviating suffering.” While a formal requirement for harm-benefit analysis only entered British law with the Animals (Scientific Procedures) Act of 1986, there was thus already some minimal regulation about acceptable research purposes. Equally, however, the Cruelty to Animals Act already contained certain requirements of refinement by prescribing the use of anaesthesia for painful experiments (article 3, sect. 3), and this did not stop Russell and Burch from thinking in greater detail about how refinement can be achieved and further improved. Thus, even though their silence about acceptable research objectives does not imply that Russell and Burch approved of just any research goal, one can ask if their unilateral emphasis on method selection rather than question selection is due to an anthropocentric tendency.

Notice, however, that the implicit prioritization of interests in the 3Rs framework is in fact more extreme than in anthropocentrism, as it assigns truly lexical priority to research objectives over animal interests. An anthropocentric approach would still have us question research objectives and minding opportunity costs. This is because these theories focus on all human interests, not just on human research or animal use interests. The 3Rs, by contrast, are built to accept the latter in every case.

Within the limits of the research objective, however, the 3Rs do not discriminate between animal interests that overlap with human interests and those that do not. Russell and Burch were concerned with animal distress ( 1959 , Chap. 2), not with how animal distress affects humans. Their emphasis on the words “humanity” and “inhumanity” can be misleading here at first glance, as it seems to highlight the moral disposition of the human agent. But Russell and Burch made it exceedingly clear that these terms must only be understood “in a purely objective sense to characterize the kind of treatment actually applied to an animal– in terms of the effect on the latter” (ibid.). While, to repeat, the mere fact that Russell and Burch focus on sentient animals or on reducing animal distress does not show that they were not anthropocentrists, the fact that they explicitly focus on animal distress irrespective of its impact on humans is indeed suggestive of a non-anthropocentric ethic.

As a preliminary result, we can see that the 3Rs concept as presented by Russell and Burch is beyond anthropocentrism in two apparently contrasting ways: On the one hand, it prioritizes the research objective so strictly that it gives even less consideration to animal interests than anthropocentrism would, apparently accepting any research objective within the confines of United Kingdom legislation at the time. But on the other, it assigns moral significance to animal distress irrespective of any relation to humans, if only within the limits set by a given research objective. The reason for this odd combination, the next section will argue, lies in the philosophy and animal welfare strategy from which the 3Rs originally arose.

The Original Moral and Strategic Commitments Underpinning the 3Rs

While Russell and Burch did not offer much in terms of ethical argumentation, their client and employer did. This was the Universities Federation for Animal Welfare (UFAW), an academic animal welfare organization, headed by its founder Charles W. Hume. His connection to the 3Rs was very close, as he had initiated the project of writing The Principles of Humane Experimental Technique , was involved in hiring decisions, and gave (sometimes rather harsh) feedback on the work in progress (Balls & Parascandola, 2019 ). Hume himself regularly spoke and wrote about scientific, philosophical, and theological issues, publishing many of his thoughts in independent scientific journals and in UFAW-edited periodicals and books (Hume, 1956 , 1962 ). These works provide a coherent approach to animal welfare ethics and organizational strategy that helps to better understand the intellectual basis of the 3Rs.

First of all, Hume’s philosophy is unambiguously non-anthropocentric. In his The Status of Animals in the Christian Religion , Hume wrote: “[…] a Christian’s duty to his neighbours cannot logically be restricted to neighbours belonging to the same species as himself. Charity is indivisible” ( 1956 , p. 73). Hume’s basic argument for this conclusion is negative: There is no good reason to exclude animals from the scope of moral obligations. Human-animal differences are gradual, not categorical, when it comes to sensation, pain, learning, reasoning, language, attention, aesthetics, emotions, personality, and perhaps even the sense of morality ( 1956 , pp. 40–49). Hume reasoned that one cannot categorically exclude animals from moral consideration based on merely gradual differences.

The only categorical distinction Hume was willing to entertain concerned the afterlife and the immortality of the soul. He was skeptical of the default Christian view that denies animals an immortal soul, questioning its theological pedigree on the grounds that it stems from Aristotle rather than scripture: “[…] the doctrine that animals have no souls which can survive death is of pagan, not Christian, origin” ( 1956 , p. 49, similarly 1962 , p. 183). The argument that most convinced Hume was that God made human souls immortal in the first place because he loves them and thus wishes to preserve them, an argument which extends to animals too ( 1962 , p. 167, 1956 , p. 50). However, for practical purposes, Hume was ready to accept the premise that animals do not have an immortal soul while humans do (see 1962 , p. 128), emphasizing that “our duty towards animals is a binding one, whether Aristotle was right or wrong” ( 1956 , p. 50). In sum, Hume made it abundantly clear that he was not an anthropocentrist. To the contrary, he had a deeply-held conviction that we have the very same duties of neighbourly love towards humans and animals alike. Footnote 4

In accordance with his non-anthropocentrism, Hume lambasted the “fanatics who say that mere animals must always be sacrificed to human interests; that any outrage, however horrible, may be perpetrated against an animal if the human race stands to gain by it” ( 1962 , p. 129). Once again, it is abundantly clear that Hume did not take human interests in using animals to be lexically superior to animal interests on moral grounds.

Second, Hume’s moral outlook was anti-speciesist avant la lettre : “[…] is it more objectionable to hurt a man than an animal? I should say definitely not, and if anybody thinks that it is, it is pertinent to put the question ‘Why?’” ( 1962 , p. 130). On another occasion, too, Hume emphasized that when it comes to the infliction of pain, there is no morally relevant distinction between humans and animals ( 1956 , p. 52).

The implications of Hume’s anti-speciesist view were limited, however, by a more specific argument about the ethics of killing. “To kill an important being is a more serious matter than to kill an unimportant one […]. Human beings are more important than animals, and it is a much more serious thing to kill a man than to kill an animal” ( 1956 , p. 51). By “importance,” Hume meant historical irreplaceability, as his example reveals: “If a cock sparrow is killed by the cat, his hen will in due course find another mate”, but “if the eleven apostles had all been executed on the first Good Friday, there would have been no Christian Church and no Christian civilization. Truly they were of more value than many sparrows” (ibid.). Hume also acknowledged that his view implies that killing people of great historical significance is a greater injustice than killing ordinary folk, but he emphasized again that inflicting pain on both is equally unjust (ibid.). Footnote 5

Although Hume’s argument only implies that killing animals is relatively “less serious” than killing (certain) humans, he went one step further and treated killing animals as morally neutral: “Animals are killed every day in the slaughterhouse (and legitimately, provided they be killed humanely), whereas to kill an innocent human being in peacetime is murder” ( 1956 , pp. 51–52). Hume never delved deeper into the question why killing animals should be morally unobjectionable just because it is painless, but he appeared to assume that animals are simply not harmed by death: “There is no harm in killing animals provided it be done painlessly” ( 1962 , p. 130). While this claim became the object of intense philosophical dispute only considerably later (see Kasperbauer & Sandøe, 2016 ), Hume also did not engage with opposing views that would have been available to him, such as Henry Salt’s ( 1894 ) writings in defense of a right to life for animals.

The strength of Hume’s conviction that animal death is unproblematic deserves emphasis. Apart from painless slaughter, he also endorsed the practice of killing “unwanted puppies and kittens” on the grounds that “only a small percentage of animals can reach maturity in any case, for otherwise there would soon be no room left in the world” ( 1962 , p. 130). Another of his examples involved animal testing: “A method of testing milk for tubercular infection consists in injecting a preparation into guinea-pigs, killing the animals painlessly before the disease has reached a stage where it can cause any suffering, and then making a post-mortem examination. Nobody can reasonably object to that” (ibid.). Footnote 6

Hume’s views had a strong impact on the aims and methods of UFAW. The organization’s stated aim was “to reduce the sum total of pain and fear inflicted on animals by man” (UFAW, 1952 ), but not to reduce the number of animals killed. In fact, painless killing was a central method of distress reduction for UFAW. The organization published a series of pamphlets on “Kind Killing” that included instructions on how to gas, shoot, or knock dead animals of various species (UFAW, 1950 , 1967 ; see also Nature, 1955 ). The organization also devoted extensive time and resources to determine the conditions under which electrocution was painless in meat production (Hume, 1962 , pp. 71–92), while never recognizably supporting lower meat consumption or collaborating with any vegetarian societies of its day. Overall, UFAW in Hume’s day devoted considerable efforts to the promotion of painless killing as a method of reducing distress. Russell and Burch, too, hail working with painlessly killed animals as a harmless replacement technique ( 1959 , Chap. 5).

However, even if one shares Hume’s moral views, they do not explain why the 3Rs treat research objectives as having lexical priority over animal welfare. We have seen that Hume endorsed a non-anthropocentric and anti-speciesist view that emphatically denied that death is a harm to animals, but such an approach could still advocate that certain research questions should not be investigated simply because they would require great animal suffering, or that one should purposely choose one’s research objectives so that they are achievable without animal distress. To understand why Russell and Burch did not develop a framework that instructs researchers to do this, we must consider not just Hume’s moral views but also the strategic views he expounded in his writings.

Hume’s strategy rested on two key commitments: The first was that strategies should be determined by facts, not feelings ( 1962 , p. 13). Both sides of the coin– being guided by facts and not being guided by feelings– were important for UFAW’s organizational identity. Given its academic background, UFAW laid emphasis on taking a scientific approach to animal welfare issues (Hume, 1962 , p. 14). According to Hume, UFAW prioritized issues in proportion to the intensity and duration of suffering involved, the number of animals affected, and the feasibility of practical reforms ( 1962 , p. 15). On the flipside, Hume thought that laypeople are poor judges of what should be done for animals due to ignorance and sentimentality– “the welfare of animals depends on factors lying beyond the ken of many animal-lovers” ( 1962 , p. 14). He thus emphasized that UFAW did not choose its policies by popularity and was not influenced by “cranky pressure groups” ( 1962 , p. 15). To Hume’s mind, this was the problem of traditional animal welfare organizations who devoted too much of their time to rescuing stray animals and of antivivisectionists who made popular, but unrealistic demands ( 1962 , pp. 13–14). UFAW also ran ads that read “are you interested in animals without being a fanatic?” (UFAW, 1958 ), emphasizing its anti-sentimental and pragmatic approach.

The second key commitment of Hume’s strategy lay in cooperating with agents who use animals rather than challenging them, such as farmers and scientists. For a start, Hume fundamentally rejected any adversarial approach to political activism, writing that “perhaps the most important rule of all for avoiding quarrels and resentments is this: never to impute motives ” (16, original emphasis). By this he meant that one should not assume any ill will on the part of animal users. This approach is also clearly reflected in Chap. 2 of the Principles , where Russell and Burch emphasize in all-capital letters that their terms “humanity” and “inhumanity” “MUST NOT BE TAKEN TO IMPLY ETHICAL CRITICISM OR EVEN PSYCHOLOGICAL DESCRIPTION OF PERSONS PRACTICING ANY GIVEN PROCEDURE” ( 1959 , Chap. 2, original capitalization).

In principle, however, even if one does not assume any ill will on the part of animal users, one could approach them in a challenging rather than cooperative way. As a rule, Hume and UFAW did not do this. “Most people, in this country at all events, have some sympathy for animals”, Hume wrote ( 1962 , p. 16), continuing: “With this fact in mind, UFAW tries to enlist the help of persons who are actively engaged in occupations which entail a risk of suffering for animals” (ibid.). His operative assumption, it appears, is that most people who use animals would prefer to safeguard animal welfare, other things being equal.

It is noteworthy that this approach was taken not just towards animal researchers, but also rabbit trappers and even whalers ( 1962 , pp. 16–17). For rabbit trappers, Hume and his colleagues advocated using a particular, supposedly less painful trap called the Lewis Humane Snare– a campaign for which Hume later apologized, apparently considering it misguided in hindsight ( 1962 , p. 30). For whalers, UFAW promoted the electric harpoon as a refinement alternative to explosive harpoons, but this innovation never took off ( 1962 , p. 215).

It is this maximum of charity towards, and willingness to cooperate with, animal users that truly explains why the 3Rs treat research objectives as sacrosanct and focus only on promoting more humane ways of achieving them, effectively assigning lexical priority to research interests over animal interests. Footnote 7 When it came to animal research, Hume and UFAW sought to enlist animal researchers as voluntary collaborators, which was possible only if their research objectives were accepted as given.

In conclusion, it is by no means moral anthropocentrism that led Russell and Burch to treat research objectives as sacrosanct, but a general strategic approach of cooperating with animal users rather than challenging them. This strategy led Hume’s non-anthropocentric, anti-speciesist moral outlook to promote a 3Rs framework that disregards animal interests even more than anthropocentrism.

The Limited Justification of Hume’s Strategy

It is not difficult to see the appeal of Hume’s strategy. It avoids direct conflict with vested interests in using animals by focusing on the scientific investigation of ways in which these interests could be satisfied in more humane ways. However, it is worth reflecting critically on the approach and its assumptions.

First, Hume’s claim that everyone has a baseline of sympathy for animals ( 1962 , p. 16) deserves some critical attention. This claim is crucial because it explains why seeking cooperation with vested interests, including rabbit trappers and whalers, is not futile for an animal welfare organization. The problem is that almost any measure to safeguard animal welfare– be it only to switch from an explosive harpoon to an electric one– involves some transition costs. Personnel may need to be retrained (risking resentment and conflict), procedures redesigned, equipment acquired or rearranged. So Hume’s strategy cannot be justified by appealing to the modest assumption that animal users will prefer the more animal-friendly option if all other conditions are equal, but must assume the bolder claim that sympathy can even motivate them to accept extra costs to some relevant degree. Of course, one can argue, as did Russell and Burch ( 1959 , Ch. 7), that humane techniques come with added benefits for humans, such as better data. But even then, there must be some reason why these benefits were not already sought. Among seasoned veterans of a given animal-using trade, this reason will often not be plain ignorance of better options, but transition costs. It is not enough for a more humane harpoon to be more economical once installed, but it also needs to be affordable, easy enough to install and use, and accepted by the crew. Hume’s strategy rests on the fundamental trust that animal users will accept transition costs due to their sympathy for animals. But this is likely true for some agents in some circumstances, not for others. It was evidently not true for whalers, as Hume himself admits that the electric harpoon failed due to “obstruction by gunners” ( 1962 , p. 215).

Yet, contrary to the evidence, Hume assumed as a matter of principle that anyone is sympathetic enough to accept extra costs for the sake of animal welfare. His reasons for this assumption are not entirely clear, but could be sought in his Christian values or in his national pride, since he primarily ascribed sympathy to British people (ibid.) and repeatedly highlighted that other countries were much more cruel to animals ( 1962 , pp. 49, 63, 92, 123, 126–128, 203–204). Hume even blamed the failure of the electric harpoon on Japanese influence ( 1962 , p. 215). Whatever the reasons for Hume’s blanket assumption of sympathy may have been, they seem questionable from a facts-based standpoint. Sometimes, a force stronger than sympathy may be required to motivate animal users to cooperate, such as economic interests or the threat of legal repercussions.

Secondly, in what conditions is Hume’s strategy advisable? Trying to enlist the voluntary cooperation of vested interests may be prudent if one is in a position of relative powerlessness. When rabbit trappers, whalers, and animal researchers have plenty of resources, far-reaching networks, and the law on their side, they are under no pressure to do as activists ask. This is a basic strategic problem for activists. But rather than attempting to reduce the power differential, say, by building up a more powerful movement for animals or by lowering the public standing of vested interests by launching outrage campaigns, Hume and early UFAW chose to work within the power differential. Their approach can be understood to offer low-cost (but not no-cost) animal welfare solutions, such as the Lewis Humane Snare, the electric harpoon, and humane experimental techniques. The key function of these solutions is to appeal to the conscience of the animal users themselves in order to achieve small-but-tangible benefits for animals.

That Hume’s cooperative approach was conditional on a power differential can be seen from the starkly different way he wrote about cruelty in young boys: “Many boys pass through a sadistic phase in which they destroy birds’ nests, maltreat young birds, inflate frogs, torture hedgehogs, etc. Such cases call for either psychiatric or castigatory treatment but are all too common” ( 1962 , p. 217). It would obviously be absurd to call for a cooperation with young boys to determine scientifically how they might inflate frogs in more humane ways, perhaps by killing the frogs painlessly first. Adults have power over children, so the problem is straightforwardly addressed by mandatory rules and not voluntary cooperation.

Obvious as it is, the conditionality of Hume’s strategic approach on a position of relative powerlessness is important to consider. It suggests that relying on the 3Rs framework, with its hands-off approach to the choice of research objectives, may be more justified in some contexts and less justified in others. It makes some strategic sense for animal welfare organizations because they have no influence over what objectives are being researched. But it does not make the same strategic sense for governments who regulate and fund research. In spite of this, the 3Rs remain central to many governments’ attempts to promote animal welfare in science (see Neuhaus et al., 2022 for an overview).

Of course, in a liberal spirit, governments may want to refrain as far as possible from exercising their power to ban any forms of research. But they also have the power to fund some types of research more than others, and to fund research infrastructure, networks, platforms, and conferences according to their own policy goals. They also have the power to create new institutional bodies to oversee and advise on progress. More ideas for how governments can go beyond the 3Rs can be found in political calls for phase-out planning for animal experimentation (see Müller, 2024 for an overview). If a government today recognizes animals as worth protecting for their own sake (as many do, see Kotzmann, 2023 ), then it should consider policy measures beyond the mere allocation of resources to the 3Rs.

This article has argued that the 3Rs should not be understood to rest on an anthropocentric moral theory, pace previous contributions. A more compelling rationale for the framework’s prioritization of research interests over animal interests is that it rests on an animal-centered ethic that is restricted by strategic considerations in line with the thinking of C. W. Hume. The article closed with critical comments on this strategic approach, highlighting in particular that animal users’ willingness to cooperate should be judged by the evidence, not based on a blanket principle of charity, and that the cooperative approach is advisable mainly in positions of relative powerlessness. This suggests that governments, who hold various forms of power in their jurisdiction, should explore ways to influence the selection of animal-friendly research objectives and not focus solely on the 3Rs and humane experimental technique.

By a “human” research objective, I mean an objective chosen by the human researcher, not necessarily an objective aiming only at benefit for humans. Even if research aims at benefits for animals (be it the very animal under study, some or all of its conspecifics, or other animals), one can ask why Russell and Burch did not articulate a framework for animal-friendly question selection, but rather one for animal-friendly method selection, accepting questions as given. Direct moral consideration of animals could motivate a much more cautious approach to how we try to benefit them, including that we do not easily harm some animals for the sake of other animals.

While the research purpose is indeed taken for granted by Russell and Burch, some more recent approaches to the 3Rs consider reformulation of the research question a form of replacement. This is taught, for instance, in a course by the European Union’s Education and Training Platform for Laboratory Animal Science (ETPLAS, 2021 ). However, reformulation can only reasonably count as a form of replacement if the research objective remains the same (Kramer, 2023 ), such as finding a safe and effective treatment for some given condition. So even at its most progressive, current 3Rs teaching has departed only to a limited extent from Russell and Burch’s approach that targets method selection but not topic selection.

Marino ( 2020 ) also criticizes this prioritization but does not use the term “anthropocentrism.”

Hume’s explicitly religious argumentation further undermines the claim that the 3Rs are a utilitarian construct at heart (see section “ The 3Rs and the Notion of Anthropocentrism ”), as this would make it a secular approach. Hume’s ethic is better understood as based on a Christian idea of neighbourly love that extends beyond the species.

An implication Hume apparently did not see is that there could be people so historically replaceable that killing them is like killing a sparrow, and that these would make for excellent scientific models of the human body. Thus, even though this was certainly not Hume’s intention, his view might inadvertently imply the permissibility of experimenting on certain painlessly killed humans.

Of course, all it would take to reasonably object to that is the view that death is, in fact, a harm to animals.

Again, it may be noted that the Cruelty to Animals Act of 1876 contained some conditions for acceptable study purposes, but this does not explain why Russell and Burch did not try to improve on this aspect of the Act. They did, by contrast, try to improve on the Act’s requirement for refinement in the form of anaesthesia. This emphasis is best explained by UFAW’s organizational focus at the time.

Abbey, R. (2007). Rawlsian resources for animal ethics. Ethics and the Environment , 12 (1), 1–22.

Article   Google Scholar  

Balls, M. (2009). The origins and early days of the three Rs concept. ATLA , 37 , 255–265.

Google Scholar  

Balls, M. (2013). UFAW and Major Charles Hume. ATLA , 41 , 1–3.

Balls, M., & Parascandola, J. (2019). The emergence and early fate of the three Rs concept. Alternatives to Laboratory Animals , 47 (5–6), 214–220.

Beauchamp, T. L., & DeGrazia, D. (2020). Principles of animal research ethics . Oxford University Press.

Brennan, A., & Lo, N. Y. S. (2022). Environmental ethics. In E. N. Zalta (Ed.), Stanford encyclopedia of philosophy (Summer 2022). https://plato.stanford.edu/archives/sum2022/entries/ethics-environmental/

Callanan, J. J., & Allais, L. (Eds.). (2020). Kant and animals . Oxford University Press.

Camenzind, S., & Eggel, M. (2022). The 3Rs principles and genetic pain disenhancement. Animal Welfare , 31 , 495–503.

Carruthers, P. (2002). The animals issue: Moral theory in practice . Cambridge University Press.

Denis, L. (2000). Kant’s conception of duties regarding animals: Reconstruction and reconsideration. History of Philosophy Quarterly , 17 (4), 405–423.

Egonsson, D. (1997). Kant’s vegetarianism. The Journal of Value Inquiry , 31 (4), 473–483. https://doi.org/10.1023/A:1004295530520

ETPLAS (2021). EU-52: Searching for (existing) non-animal alternatives . Education and Training Platform for Laboratory Animal Science. https://learn.etplas.eu/courses/eu-52/

Fox, M. A. (1998). Anthropocentrism. In M. Bekoff (Ed.), Encyclopedia of animal rights and animal welfare (pp. 66–68). Greenwood.

Hay, C. (2020). What do we owe to animals? Kant on non-intrinsic value. In J. J. Callanan, & L. Allais (Eds.), Kant and animals (pp. 176–190). Oxford University Press.

Hayward, T. (1997). Anthropocentrism: A misunderstood problem. Environmental Values , 6 , 49–63. https://doi.org/10.3197/096327197776679185

Hobson-West, P. (2009). What kind of animal is the ‘Three Rs’? Alternatives to Laboratory Animals , 37 (2), 95–99.

Hume, C. W. (1956). The status of animals in the Christian religion . Universities Federation for Animal Welfare.

Hume, C. W. (1962). Man and beast . Universities Federation for Animal Welfare.

Jaworska, A., & Tannenbaum, J. (2018). The grounds of moral status. In The Stanford encyclopedia of philosophy . https://plato.stanford.edu/archives/spr2018/entries/grounds-moral-status/

Kagan, S. (2019). How to count animals, more or less . Oxford University Press.

Kasperbauer, T. J., & Sandøe, P. (2016). Killing as a welfare issue. In The ethics of killing animals (pp. 17–31). Oxford University Press.

Kotzmann, J. (2023). Sentience and intrinsic worth as a pluralist foundation for fundamental animal rights. Oxford Journal of Legal Studies , 43 (2), 405–428. https://doi.org/10.1093/ojls/gqad003

Kramer, K. (2023). When is something an alternative? A general account applied to animal-free alternatives to animal research. Cambridge Quarterly of Healthcare Ethics , 33 (1), 89–101. https://doi.org/10.1017/S0963180123000300

Landi, M. S., Shriver, A. J., & Mueller, A. (2015). Consideration and checkboxes: Incorporating ethics and science into the 3Rs. Journal of the American Association for Laboratory Animal Science , 54 (2), 224–230.

Lauwereyns, J. (2018). Rethinking the three R’s in animal research . Springer.

Macdonald, P. A. (2021). Acknowleding animal rights: A thomistic perspective. American Catholic Philosophical Quarterly , 95 (1), 95–116.

Marino, L. (2020). Commentary: A Belmont report for animals? Rights or welfare? Cambridge Quarterly of Healthcare Ethics , 29 , 67–70.

Müller, N. D. (2022). Kantianism for animals: A radical Kantian animal ethic . Palgrave Macmillan.

Müller, N. D. (2024). Phase-out planning for animal experimentation: A definition, an argument, and seven action points. ALTEX , 41 (2), 260–272. https://doi.org/10.14573/altex.2312041

Nature. (1955). Humane killing of animals. Nature , 176 , 862. https://doi.org/10.1038/176862a0

Neuhaus, W., Reininger-Gutmann, B., Rinner, B., Plasenzotti, R., Wilflingseder, D., De Kock, J., Vanhaecke, T., Rogiers, V., Jírová, D., Kejlová, K., Knudsen, L. E., Nielsen, R. N., Kleuser, B., Kral, V., Thöne-Reineke, C., Hartung, T., Pallocca, G., Leist, M., Hippenstiel, S., & Spielmann, H. (2022). The rise of three Rs centres and platforms in Europe*. Alternatives to Laboratory Animals , 50 (2), 90–120. https://doi.org/10.1177/02611929221099165

Regan, T. (2004). The case for animal rights . University of California Press.

Russell, W. M. S., & Burch, R. L. (1959). The principles of humane experimental technique . Methuen.

Salt, H. S. (1894). Animals’ rights considered in relation to social progress . Macmillan & Co.

Schuppli, C. A., Fraser, D., & McDonald, M. (2004). Expanding the three Rs to meet new challenges in humane animal experimentation. ATLA , 32 , 525–532.

Scott, C. D., & Coetser, Y. M. (2015). Rewriting Aquinas’ animal ethics: The primacy of reason in the determination of moral status. South African Journal of Philosophy , 34 (3), 289–303.

Tannenbaum, J., & Bennett, B. T. (2015). Russell and Burch’s 3Rs then and now: The need for clarify in definition and purpose. Journal of the American Association for Laboratory Animal Science , 54 (2), 120–132.

UFAW. (1950). Kind killing . Universities Federation for Animal Welfare.

UFAW. (1952). The Universities Federation for Animal Welfare . Universities Federation for Animal Welfare.

UFAW (1958). Advertisement. South African Journal of Medical Laboratory Technology , 4 (2). https://archive.org/details/sim_south-african-journal-of-medical-laboratory-technology_1958-06_4_2/page/n5/mode/2up?q=kind+killing

UFAW. (1967). Humane killing of animals . Universities Federation for Animal Welfare.

Vorstenbosch, J. M. G. (2005). The ethics of the three Rs principle: A reconsideration. Animal Welfare , 14 , 339–345.

Walker, R. L., & Eggel, M. (2020). From mice to monkeys? Beyond orthodox approaches to the ethics of animal model choice. Animals , 10 (77). https://doi.org/10.3390/ani10010077

Warren, M. A. (1997). Moral status: Obligations to persons and other living things . Clarendon.

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Acknowledgements

The author thanks three anonymous reviewers of this journal, as well as managing editor Lida Anestidou, for their helpful feedback.

Funding provided by Swiss National Science Foundation, National Research Programme 79 “Advancing 3R: Research, Animals and Society” (Grant No. 407940_214850)

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Müller, N.D. Beyond Anthropocentrism: The Moral and Strategic Philosophy behind Russell and Burch’s 3Rs in Animal Experimentation. Sci Eng Ethics 30 , 44 (2024). https://doi.org/10.1007/s11948-024-00504-1

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Extended Examples: Nonhuman Animals

THE ENVIRONMENTAL ETHICS IN GENERAL

PRELIMINARIES

The environmental ethics is an attempt to provide rational and morally well supported answers to issues related to the moral status of non-human beings (i.e., non-human animals and nature or objects in nature). Here are some examples of questions pursued in the domain of environmental ethics: 

Why should we care about the planet and the non human residents of our planet?

Do we have any obligations to future generations?

Can we use animals and nature in any way that suits us?

Do they have moral rights?

On what foundations should we rest our concern for rain‑forest, marine ecology, or natural landscapes?

TWO GENERAL STYLES OF ARGUMENTS USED IN EE:

Morally‑Indirect Environmental Strategies (or "the indirect duty" view) (part of homo-centrism, e.g., Aquinas, Kant)):

We ought to protect the natural environment because, in the long run, it is good for humans.

Ex1: It is wrong to destroy rain forest because deforestation negatively affects current and future humans

Ex2: It is wrong to use up non-renewable resources because, in a long run, it is bad for humans. In particular, future generations of humans will be negatively effected by our actions.

Ex3: It is wrong to be cruel to animals, because it may lead to cruelty to humans.

Ex4: It is wrong to be cruel to my dogs because they are my property and I do ot want my property to be used in certain ways.

Morally‑Direct Environmental Strategies ("the direct duty" view; e.g., Singer, Regan, Sencerz ):

We ought to protect the natural environment because it is good for natural environment. That is, something in the natural environment has intrinsic (or inherent) value that (morally) has to be taken into consideration.

Ex1: It is wrong to be cruel to animals because it causes them pain. (Singer, Sencerz, utilitarians)

Ex2: It's wrong to harm animals because they are subjects of a life and thus, they have special dignity inherent value and moral rights. (Regan)

Ex2: It is wrong to destroy rain forrest because it is beautiful and beauty has intrinsic vale.

THREE GENERAL / BASIC POSITIONS IN THE ENVIRONMENTAL ETHICS

i) TRADITIONAL AND PROTRACTED HUMANISM (HOMO-CENTRISM, HUMAN CHAUVINISM, SPECIECISM )

A) Only humans (both current and future) have moral standing (morally matter).

B) The natural environment must be protected only in so far as it is good for humans.

C) Animals are excluded from the sphere of morality; we only have indirect duties to them. (That is, all limitations about what we can do to or with animals and nature are explained by the means of indirect environmental strategies.)

Some examples

* Aquinas (and the traditional Natural Law Theory, see quotations in Rachels)

* Kant (and his interpretation of categorical Imperatives)

* Rational egoists and egoistically inclined contractarians such as Thomas Hobbes. 

Hobbes maintained that morality is a result of agreement between rational et egoistical beings who make a contract to adopt and follow certain rules (irrational and non-rational being cannot enter into any such contract). Notice, contractarians immediately run into a problem of explaining why we have duties to future generations, children, and other beings who cannot enter into a contract with us. 

ii) INDIVIDUALISTIC EXTENSIONISM : 

The same basic ethical principles govern our attitude to both humans and animals. That is, we have direct obligations to both humans and animals.

Ex 1: Classical and Contemporary Utilitarians (the following passage comes from Peter Singer's book "Animal Liberation"; see  also his " All animals Are Equal "): 

Jeremy Bentham incorporated the essential basis of moral equality into his utilitarian system of ethics in the formula: “Each to count for one and none for more than one.” In other words, the interests of every being affected by an action are to be taken into account and given the same weight as the like interests of any other being. A later utilitarian, Henry Sidgwick, put the point in this way: "The good of any one individual is of no more importance, from the point of view (if I may say so) of the Universe, than the good of any other.'' [The Methods of Ethics  (7th Ed.), p. 382.] More recently, the leading figures in contemporary moral philosophy have shown a great deal of agreement in specifying as a fundamental presupposition of their moral theories some similar requirement which operates so as to give everyone's interests equal consideration — although they cannot agree on how this requirement is best formulated.

If a being suffers, there can be no moral justification for refusing to take that suffering into consideration. No matter what the nature of the being, the principle of equality requires that its suffering be counted equally with the like suffering—in so far as rough comparisons can be made—of any other being. If a being is not capable of suffering, or of experiencing enjoyment or happiness, there is nothing to be taken into account. This is why the limit of sentience (using the term as a convenient, if not strictly accurate, shorthand for the capacity to suffer or experience enjoyment or happiness) is the only defensible boundary of concern for the interests of others. To mark this boundary by some characteristic like intelligence or rationality would be to mark it in an arbitrary way. Why not choose some other characteristic, like skin color?

The full quote from Bentham is in Rachels (7th ed., p. 106)

Ex 2: Contemporary Kantians (e.g., Tom Regan )

Regan utilizes Kant's like insights, specifically the idea that some beings must never be used merely as a means; he extends this ideas to include animals.

Regan's first point is factual. Namely, he claims that all beings with a mental development of about 1 year old mammal are "subjects of a life."  Such being have a subjective point of view and likings and preferences. Consequently, their lives may be better or worse for them from their subjective point of view. (By contrast, cars can run better or worse but they do not care about it because they have no subjective point of view.)

Regan's second point is normative ; namely he claims that "all subjects of a life have an inherent value".

Notice, Regans' concept of inherent value is an analog of what Immanuel Kant called the special worth and special dignity . (Read again Rachels, chapters 1, 9-10 and this set of notes about deontology, Kant, and the Ethics of respect for persons .) There are are, of course, some differences between Kant and Regan. Kant links the concept of the "special worth" and "special dignity" to rationality and autonomy. Regan links it to having a subjective point of view and being "the subject of a life". 

Finally, Regan argues that all beings who have inherent value must not be used merely as means to promote utility. Such beings have moral rights. In particular, they have a right not to be harmed. 

iii) GLOBAL EXTENSIONISM (ECOCENTRISM) :

Some non‑sentient beings and systems have moral standing. They may include individual plants, species, ecosystems, even the nature as a whole.

Ex 1: Aldo Leopold: 

"All ethics... rest upon a single premise: that the individual is a member of a community of interdependent parts... The land ethics simply enlarges the boundaries of the community to include soils, waters, plants, and animals, or collectively: the land" (Aldo Leopold, A Sand County Almanac (New York: Ballantine, 1966), p. 239).

Ex 2: Baird Callicott: 

"[land ethics] is in sharp contrast to traditional Western humanism... [it] provides moral standing for both environmental individuals and for the environment as a whole". Leopold: "a land ethics changes the role of Homo Sapiens from conqueror of the land community to plain member and citizen of it. It implies respect for fellow members and also respect for the community as such" (J. Baird Callicott, "The Search for an Environmental Ethics" in William Shaw, Social and Professional Ethics, 2nd ed., p. 199).

SOME PROBLEMS FOR ALL MORALLY-INDIRECT APPROACHES TO ENVIRONMENT:

There is a consensus that, if an action or practice negatively affects humans (current and future), we have a reason not to do it. The question is, is this all there is about animal ethics? That is, do these indirect arguments go far enough? Are they sufficient to deal with all forms of animal and environmental abuse?  Are there some other good and more direct arguments that support changing our attitudes to animals?

A) An intuitive approach .

In general, suffering is treated as intrinsically bad, period. So, animal suffering is also bad.  Therefore, animal suffering always matters from a moral point of view?

B) The last man on a desert island argument(s) .

Suppose that some action causes excruciating suffering to an animal yet has no adverse bad results for humans. For example, someone tortures animals on a desert island and then dies. It seems obvious such an action is morally wrong. But the indirect approach cannot explain why. So it has to be rejected.

C) Arguments from marginal cases

Suppose we deal with a child who will never develop into a rational being. Intuitively, we ought not cause such a child unnecessary suffering. So, morality does not seem to depend on someones's being rational but rather on someone's being sentient (i.e., having an ability to suffer and feel pleasure). But animals have this ability. So, they are in the sphere of moral concern. 

D) Other Possible Natural Objects That May Have Intrinsic Value

It is harder to argue that we have to extend the sphere of moral concern to non-sentient beings and/or systems. Some philosophers argue that, e.g., the ground for this step may be provided by the fact that these objects are beautiful and beauty has intrinsic value.

APPLICATIONS: RAISING ANIMALS FOR CONSUMPTION

Some general points

An Argument from Marginal Cases (again) : Both Singer and Regan notice that it would be morally wrong to use severely handicapped humans (e.g., severely enfeebled children) in ways we currently use animals. The consistency requires to treat similar cases similarly. Thus, they argue, most experiments on animals are morally wrong and we ought to abandon industrial methods of producing meat, dairy, and eggs (so called, the factory farms). 

Some differences in their approaches: Singer would allow for using an animal when it maximizes utility. Regan's approach is deontologist (neo-Kantian); he argues that what we do to animals involves treating them merely as a means, violates their moral rights, and thus is wrong. We should stop doing it even if it maximizes utility. 

MAIN REASONS AGAINS RAISING ANIMALS FOR FOOD

Harms to animals

(from Sencerz, "Toward a Plausible Hierarchical View About Animals", in progress)

A great majority of animals raised for food in the industrial world are raised on factory farms under conditions causing them excruciating suffering, typically throughout their lives. Hens and chickens almost always live in hangars full of methane destroying their eyes; these conditions are repeated for about 99% of all farm animals in the United States. For the sake of space and energy efficiency, 99.9% of chickens raised for meat and 98.2% of hens raised for eggs are forced into stacks of layered “battery” cages where they live on wiry floors that break and damage their legs. To force quicker growth and to save on food, they share a small cage with three to eight other birds; the space allocated to each is so small that they cannot stretch out their wings or turn around. Their normal instinctual behavior is to peck at each other until one of them moves away. But this cannot happen in a small cage. Thus, if this instinctual behavior were not gotten under control, they would peck at each other until one of them drops dead, causing a loss to a producer. To prevent this behavior, they are debeaked with a hot blade cutting off the tips of their beaks through a thick layer of highly sensitive tissue. The process causes lasting pain and impairs their abilities to eat and drink. This happens several times during their lives. This horror is the fate of about 3 billion hens and chicken per year in the United States alone. Another billion or so are killed immediately when they are hatched, usually by suffocation or by being grinded alive simply because they are male and so they cannot produce eggs. Consequently, raising them is less profitable than raising female birds. In the United States, there are no legal constraints upon raising birds. Farmers can do to them literally whatever they want.

Calves are separated from their mothers shortly after birth so more milk can reach the market. Naturally, it causes stress and suffering to all of them. Cows are forced to have new offspring year after year, and they are slaughtered as soon as they cannot continue doing it. These are not just examples of excesses. Rather, they illustrate what is a standard for the food industry. Veal calves are kept in small stalls, 22” by 54”, and are chained by their necks so they cannot move or turn around. Again, it saves on food and generates faster growth. They are raised on a liquid iron-deficient diet causing anemia so the veal looks better and fetches a better price. Beef cattle are kept on hard surfaces in feedlots frequently housing up to 100,000 animals. Since they cannot move around, they must stand in their own waste. These conditions cause chronic feet and leg injuries. Pigs are confined in iron crates providing about 6 square feet of space that are situated on concrete floors with no bedding of any kind. They are forced to breed over and over again.

Animals raised in these circumstances cannot fulfill their most basic instinctual needs such as nursing, stretching, moving around, rooting, grooming, establishing their social order, selecting mates, procreating, or rearing their offspring. This leads to an extreme boredom and depression, which induces stress and the suppression of their immune systems. To prevent the large-scale losses caused by disease, animals are routinely fed antibiotics and growth hormones. In turn, they are transported frequently for hundreds of miles in confinement in extreme heat or cold before they are slaughtered.

To put some numbers on it (and not counting horses, goats, rabbits, and fish), almost 10 billion animals are slaughtered annually in the United States alone. For example, according to the United States Department of Agriculture, 9.4 billion birds, 33 million cattle, .6 million calves, 124.4 million hogs, and 2.26 million sheep and lamb were killed in 2018. In addition, about 1 billion animals suffer and die from diseases, malnutrition, injury, or suffocation. This means that about 30 million animals are killed every day and about 20,000 during time it takes someone to read a page. As Mylan Engel summed up in this point, “no other human activity results in more pain, suffering, frustration, and death than factory farming and animal agribusiness” (Engel (2000, pp. 866-867)).

Fragments from "The Eartlings" https://www.youtube.com/watch?v=w8B547L5VkQ

Food (Birds) (10 minutes)

Food (Cows, Pigs ) https://www.youtube.com/watch?v=OQ4xlwEuHRI (5 minutes)

See also Part V: Science (10 minutes)

"Meet Your Meat " (11 minutes, a documentary produced by PETA)

Environmental factors and inefficiency (same source, I rely on Engel (2000, pp. 870-872)).

The meat industry is also an inefficient and environmentally damaging way of producing food. [1] First, it is about 10-11 times less energy efficient when compared to producing plants. On average, it takes 28 kilocalories of fossil fuel to produce 1 kcal of animal protein, compared to 3.3 kcal of fossil energy to produce 1 kcal of grain protein (Pimentel (1997, pp. 16, 20)). Fish production is almost as inefficient (Pimentel and Pimentel (1996, p. 93)). Second, a nimal production is extremely inefficient in its water usage. Producing 1 pound of animal protein requires about 100 times more water than producing 1 pound of plant protein. Agriculture currently accounts for 87% of the world’s fresh water use. This could be radically reduced by shifting to an entirely plant-based agriculture (Pimentel, Houser, at all (1997, p. 100)). Third, animal agriculture is also extremely nutrient inefficient. As John Robbins observed:

By cycling our grain through livestock, we not only waste 90 percent of its protein; in addition, we sadly waste 96 percent of its calories, 100 percent of its fiber, and 100 percent of its carbohydrates.

Meanwhile, malnutrition is the principal cause of infant and child mortality in developing nations. In many of them, over 25 percent of the population die before reaching the age of four. In Guatemala, 75 percent of the children under five years of age are undernourished. Yet every year Guatemala exports 40 million pounds of meat to the United States. It borders on the criminal! (Robbins (2012, p. 325))

Fourth, the meat industry causes an enormous amount of soil erosion. As Pimentel, Harvey et al (1995) summed up in this point: “During the last 40 years, nearly one-third of the world’s arable land has been lost by erosion and continues to be lost at a rate of more than 10 million hectares per year” (Pimentel, Harvey et al (p. 1117). Fifth, animal agriculture creates enormous amounts of hazardous waste in the form of excrement. Sixth, livestock farming contributes 18% of greenhouse gas emissions (Matthews, 2006), which is more than the total emission from ships, planes, trucks, cars and all other transport put together (Froggatt, Wellesley, Baile, 2014).

Public Health

Pollutants released by factory farms are serious risks for people living around them; they show higher numbers of the incidents of pneumonia, respiratory diseases, and cancer (See, for example, Horrigan, Lawrence, and Walker (2002, p. 445). Next, the livestock industry relies heavily on antibiotics used to control infections. In the United States, about 80% of all antibiotics are consumed by farm animals (“Summary Report,” Food and Drug Administration , 2014). This use of antibiotics contributes to the public health problem of antibiotic resistance. According to the European Centre for Disease Prevention and Control:

The damaging effects of antimicrobial resistance (AMR) are already manifesting themselves across the world. Antimicrobial-resistant infections currently claim at least 50,000 lives each year across Europe and the US alone, with many hundreds of thousands more dying in other areas of the world.

As this figure continues to rise, it may cause an enormous health and economic crisis. Next, there are a number of deadly zoonotic diseases that remain harmless when carried by animals but become deadly after jumping to humans. There are many examples of disease that was spread most likely through the consumption of infected meat. H1N1 influenza, known as the so-called “Spanish Flu,” killed about 50 million people beginning in 1918. HIV/AIDS has been traced to chimpanzees living in Central Africa. In 2018, 770,00 people died from causes related to HIV. The Ebola virus has spread to humans from infected bats or infected non-human primates. The H1N1 influenza, again, this time known as the “Swine Flu,” killed about a quarter million people in 2009-2010. And the novel virus, COVID-19, has already killed more than 1.2 million people globally. In addition, the industry has a devastating impact on workers who make the production of meat possible. As one of the slaughterhouse workers noticed:

Every sticker [slaughterhouse killer] I know carries a gun, and every one of them would shoot you. Most stickers I know have been arrested for assault. A lot of them have problems with alcohol. They have to drink, they have no other way of dealing with killing life, killing animals all day long. If you stop to think about it, you’re killing several thousand beings a day. (Eisnitz (1997, p. 87))

It would seem possible to eliminate almost all of these problems if we were to adopt a vegan lifestyle. In fact, most of these problems would be eliminated if we allowed ourselves some limited access to animal products, i.e., milk and eggs, on the assumption that we can develop completely symbiotic relations with animals.

Personal health

There are literally hundreds of scientific studies, published in top scientific journals, demonstrating that vegan and/or low-fat vegetarian diets leads to lower rates of coronary heart diseases, significantly lower rates of heart attacks, cancers, diabetes, hypertension, strokes and other degenerative diseases (typically between 10-20% of rates for meat eaters), and generally live longer lives. In addition, there are numerous examples of world class athletes who are vegan and vegetarians. A partial list includes Dave Scott (six-time winner of Hawaii’s Ironman Triathlon), Sixto Linares (world record holder for the 24-hour triathlon), Edwin Moses (400 meters hurdler undefeated in international competition for eight straight years), Paavo Nurmi (held twenty world records and nine Olympic medals), Andreas Cahling (1980 “Mr. International” title in body building), and Scott Jurek (arguably, the greatest ultramarathon runner of all time).

More here: “100 Scientific Reasons to NOT Eat Meat” is a sample of one hundred of such studies providing a link to, and a brief summary, of each: https://honeyforsweetnes.wordpress.com/2015/10/06/100-scientific-reasons-to-not-eat-meat/ .

ADDITIONAL RESOURCES

Movies and video-clips:  

"Food, Inc" -- A documentary making a case against "factory farms" and in support of local self-sustainable farms and also organic food. The movie argues that going away from factory farms would be best for the planet, economy, and human health. It would also greatly reduce (if not totally elliminate) animal suffering. Comes with the book. ( PBS trailer , 24 minutes long;  or google you tube)

"Forks Over Knives" (available on Netflix or google you-tube). A powerful documentary about the benefits, both individual and societal, of going vegan. It covers the same material as the book, China Study (by Campbell and co), mentionned above and below. (After watching this movie, my friend, a Ph.D. in philosophy and a meat eater observed what follows: "I'm not ready to fully go down that path, but I find the arguments compelling and the issues important.")

A CNN video of workers abusing cows ; it raises serious food safety issues. Very graphic and not for faint-hearted.

Supermarket Secrets - Dispatches part 1 and Part 2 A journalist Jane Moore investigates how supermarkets have affected the food on our plates and reveals the tell-tale signs that the food we buy may not have been grown in the way we think.

" The Earthlings " (a complete movie); another link to " The Earthlings ". (EARTHLINGS is a feature length documentary about humanity’s absolute dependence on animals (for pets, food, clothing, entertainment, and scientific research) but also illustrates our complete disrespect for these so-called “non-human providers.” The film is narrated by Academy Award nominee Joaquin Phoenix (GLADIATOR) and features music by the critically acclaimed platinum artist Moby. With an in-depth study into pet stores, puppy mills and animals shelters, as well as factory farms, the leather and fur trades, sports and entertainment industries, and finally the medical and scientific profession, EARTHLINGS uses hidden cameras and never before seen footage to chronicle the day-to-day practices of some of the largest industries in the world, all of which rely entirely on animals for profit.)

Food (Birds) (10 minutes) 

"Meet Your Meat " (11 minutes long documentary produced by PETA)

Animals Should Be Off the Menu (10 minutes): Philip Wollen addresses the St James Ethics and the Wheeler Centre debate making a case that animals ought to be off the menu because it is good for them, for us, and for our planet. One of the most powerful speeches on this topic I have ever seen.

Animals Should Be Off the Menu: The full debate (113 minutes): A very good debate on both sides. The topic is, strictly speaking, "Should Animals Be Off the Menu". Singer and Wollen gave extremely powerful arguments against factory farms. The other side argues, mostly, for self-sustainable farms (which has nothibg to do with the abomination of the factory farms). 

Other (mostly on line) resources

Sencerz, Environmental Ethics Page   -- please notice extensive links at the bottom of the page.

Texts by Peter Singer http://www.animal-rights-library.com/authors-m/singer.htm

Peter Singer, "All Animals Are Equal"

Tom Regan, "The Case for Animal Rights" ( a fragment ).

T. Collin Campbell and Thomas M. Cambell, The China Study (2006), (a comprehensive study of various diets and life styles and their effects on our longevity and health. Free download (PDF) ; Wikipedia summary

Frances Moore Lappe, Diet For a Small Planet ( free copy in PFDF ), the book is very comprehensive including recipes and analysis of environmental impact of meat industry

Michaell Pollan's site  --  The New York Times Magazine reporter Michael Pollan offers a critical discussion of Singer's position, then follows up with a much more moderate solution to the issues of "animal liberation." It's an argument for small orgainc farms (and against factory farm industry).

William O. Stephens, “ Five Arguments For Vegetarianism " Philosophy in the Contemporary World 1:4 (1994) . Main philosophical arguments for vegetariansim explained and discused.

Stefan Sencerz, "Utilitarianism and Replacability Revisited, or Are Animals Expendable?" , Between the Species 14:1 (2011).

Stefan Sencerz, " And Then Step By Step I Went Vegan (And How Moral Principles Guided Me) " (a personal narrative)

Nutritional Update For Physicians: Plant Based Diets

QUESTIONS FOR REVIEW :

1) Both Peter Singer and Tom Regan argue that

A) in general, it is morally permissible to experiment on animals and to raise them for food, we just have to do it humanely;

B) in general, it is wrong to experiment on animals and to raise them for food (and if we do it, it would be an exception to a rule);

C) it is never permissible to experiment on an animal.

D) none of the above

2) According to Singer, the most fundamental principle of equality can be stated as follows:

A) only factually identical beings ought to be treated equally;

B) Only beings with comparable mental abilities ought to be treated equally;

C) The interests of every being that has interests are to be taken into account and treated equally with the interests of any other being;

D) All of us have certain basic equal rights, e.g., the right to life; E) All of the above.

3) According to Tom Regan, the most fundamental moral principle can be stated as follows:

A) Only factually identical beings ought to be treated equally;

B) The interests of every being that has interests are to be taken into account and treated equally with the interests of any other being;

C) No being who is a subject of a life and thus has inherent value (and thus moral right) can be treated with disregard for this being’s rights (especially the right not to be harmed), and this includes animals.

D) All of the above;  

E) None of the above

4) According to protracted humanism (homocentrism) the natural environment and animals ought to protected and respected because

A) such protection is good for current and future humans;

B) such protection is good for animals;

C) humanistic attitudes include natural landscapes;

D) all of the above; E) none of the above.

5) The following philosophers would accept the main tenets of protracted humanism (homocentrism)

A) St. Augustine and St. Thomas Aquinas

B) Kant and Hobbes;               C) Singer and Regan

D) A) and B);                           E) all of the above

6)  According to Individualistic Extensionism the following beings have moral standing (are directly protected by the rules of morality):

A) only current and future humans;

B) both humans and other sentient beings (animals);

C) humans, animals, natural landscapes and other non-sentient parts of environment;

D) none of the above.

7) The following philosophers would accept the main tenets of individualistic extensionism

B) Kant and Hobbes C) Singer and Regan

D) A) and B);

E) all of the above

8)  According to eco-centrism (global extensionism) the following beings have moral standing (are directly protected by the rules of morality):

B) both humans and sentient animals;

C) humans, andimals, natural landscapes and other non-sentient parts of environment;  D) none of the above.

9) Peter Singer position is

A) a version of consequentialism based on the view that the satisfaction of interests is good while frustration of interests is bad (pleasure is good and pain is bad);

B) a version of deontology based on the idea of respect for rights;

C) both A) and B);

10) Tom Regan position is

A) a version of consequentialism

B) a version of deontology based on the idea of respect for

11) Augustine, Aquinas and Kant argue that

A) we do not have any direct obligations to animals or nature and we can do with them whatever we feel like doing, no limitations

B) we do not have any direct obligations to animals or nature but we must not be cruel to animals for if we are cruel to animals we may become cruel to humans

C) both a) and b);

12) Imagine that the last person on a desert Island decides to take care of her pet because she thinks it is her obligation to this animal. This example seems to show that 

A)  indirect environmental strategies are morally correct (that is we do not have any direct duties to animals or nature);

B) indirect environmental strategies are morally incorrect (that is, we may have some direct obligations to animals)

C) living on a desert island is not that bad if one has enough water and food;

14) According to the argument from the “marginal cases” we ought to take care of seriously mentally handicapped people when they suffer. This argument attempts to show that

A) animals are not at all like humans; thus, we do not have any duties to them (they do not have a moral standing);

B) humans who are only marginally like us have a moral standing (we have some obligations to them); thus, similarly, animals may have a moral standing (moral constraints are not directly linked with someone’s intelligence);

C) neither A) nor B)

D) all of the above

15) If we have obligations to Neanderthal men, future humans who may have different genetic material, and even Extra Terrestrial beings, then

A) moral standing does not depend on someone’s being a human being, a member of our species (Homo Sapiens);

B) moral standing depends on someone’s being a human being, a member of our species;

C) neither A) nor B.

16)  Stef argued in class that one reason to care about natural environment is that some natural objects are beautiful, and beauty has intrinsic value, and we have a reason to protect something which has an intrinsic value.

A) true B) false. 

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