Issues Magazine

Should Animals Continue to Be Used in Research Experiments?

By Cynthia Burnett

Animal experimentation is an established yet controversial practice. Should it continue and what are the alternatives?

In the Western world, the use of animals as a tool to learn about the human body dates back to about 200 AD to the time of Galen, who was physician to Emperor Marcus Aurelius’ family and to the gladiators of ancient Rome. At a time when no anaesthetics were known, Galen cut open live goats, pigs and monkeys in the hope of learning about how the human body works. With few lapses, the animal experimental model has continued in use right up to the present day.

Ultimately, vivisection became the term used to describe the cutting or dissection of a live animal (human or non-human), and today is largely restricted in reference to vertebrates. In today’s scientific world it is usually dropped in favour of the all-encompassing and euphemistic animal experimentation.

Scientific knowledge about non-human animals is a field that has grown exponentially since the 18th century. A great deal is now known about animal anatomy, physiology, biochemistry, neurology, habitat, behaviour and social needs. It is now realised that non-human animals are not the unthinking, unfeeling robotic machines that Cartesian science would have had us believe; rather, they are highly complex creatures capable of experiencing pain, pleasure, fear, distress, hunger, thirst and, in social species, mental and emotional deprivation if unable to interact with others of their own kind.

While it is true that humans and non-human animals (especially mammals) are anatomically and physiologically similar in general terms, a myriad of small differences between the biological systems of species make them very different indeed, and these differences have huge implications for the efficacy of the animal model. Ray and Jean Greek, in their seminal book on the fallibility of the animal model, Sacred Cows and Golden Geese: The Human Cost of Experiments on Animals (2000), explain:

Grossly, animals are alike, that is why we are all part of the animal kingdom. We differ on the cellular and molecular level, and, importantly, that is where disease occurs [sic] (p.16).

Add this information to the fast-growing body of documented knowledge about the fallibility of the animal experimental model – which can produce results that range from misleading to not applicable to humans at all or even dangerous to humans – and it is easy to see why, for the past 200 years, serious questions have been raised about not only the morality of using and killing animals for the purpose of medical research but also the value of the results obtained from such research. Even many of the results that have had some beneficial implications for human health could have been obtained by methods not using animals, rendering the need for animals unnecessary.

It is time to ask, yet again, if this approach to biomedical research should continue. Why has it lasted so long? Is it good science? Is it ethical? Is there a better way forward?

Growth in Animal Experimentation

The enormity of the business of animal experimentation – for it is a business – can be seen in the numbers of animals used. While it is difficult to establish an exact number for experimental animals used worldwide, because governments are at differing stages in establishing the parameters to be used in determining numbers, some close estimates are possible. It has been estimated that 58.3 million living non-human vertebrates were subjected to fundamental or biomedical research, toxicity testing or educational use in 179 countries in 2005. When animals killed for the provision of experimental tissues, used to maintain genetically modified strains or bred for laboratory use but killed as surplus to requirements were included, the estimate increased to a total of 115.3 million vertebrates worldwide in 2005. This figure is itself regarded as conservative.

Two of the largest users appear to be the US, which used 17.3 million animals in 2005, and Japan, where a total of 11,154,961 living non-human vertebrates were used for these purposes in 2004. In Australia the figure was close to seven million animals in 2005.

The fastest growing area of animal experimental research today is in genetically modified lab animals. A further recent development causing a huge increase in animal experimentation is the development of massive chemical testing programs intended to establish the safety of a wide range of environmental, occupational and consumer chemicals that are traded around the world.

Why Has Animal Experimentation Persisted?

There are several reasons why this paradigm has dominated for so long.

  • Medical training continued to be based on assumed similarities between human and non-human animals.
  • Many advances in medical science were attributed to the use of animals.
  • Science’s mantra is that for treatments to be effective and safe on humans, they first need to be validated using animals.
  • The public had no access to the facts in the scientific literature but were exposed to the marketing and propaganda of medical and drug cartels about new treatments.
  • The scientific community was a “closed shop” and enjoyed the luxury of little or no accountability.
  • Experimental researchers would challenge their critics with the question: “If not animals, then what?”
  • The chemical and pharmaceutical industries are powerful vested interests and the testing of drugs on animals brings considerable funding to research centres and universities.
  • Hundreds of thousands of people make a living from breeding research animals, manufacturing the food and housing used for experiments, building the labs and research centres, staffing them and doing research.
  • Change is often difficult, disruptive and costly. Those who make a living that involves animal experiments are reluctant to change methodologies for fear of failure or ridicule by peers.
  • Some countries legally require validation tests to be done on animals before clinical trials can begin.

Opposition to Animal Experimentation

Throughout the time that the experimental model was gaining its foothold, the method was not without critics, including laypeople concerned by the treatment of animals, philosophers and writers who questioned the ethics of such use, artists, musicians, royalty, scientists, doctors, religious leaders and animal rights advocates. Published anthologies cover an extensive range of views and opinions against vivisection and animal experimentation that indicate an enduring rebuttal of the practice through the centuries from all quarters.

Every time researchers publish the results of their work in peer-reviewed professional journals, the paradigm is sustained. For many years, scientists wishing to publish concerns or criticisms about the animal model were effectively denied publication in peer-reviewed journals or, if printed, were ridiculed by colleagues. Fortunately, this situation has changed and much is now published about the limitations of animal research.

Over the past 150 years, a strong anti-vivisection movement has grown from small beginnings to become a worldwide influence. Among the very many organisations that exist, some of the larger, more active and well resourced groups are the British Union Against Vivisection; Fund for the Replacement of Animals in Medical Experiments; the New England Anti-Vivisection Society, USA; the New Zealand Anti-Vivisection Society; the Physicians Committee for Responsible Medicine; the American Association of Veterinarians for Animal Rights; the Dr Hadwen Trust for Humane Research; and the Australian Association for Humane Research and Medical Advances without Animals (Australia).

The aim of the animal rights movement, with its roots in the early 1970s, is to expand the heritage of animal welfare to one of consideration for the species-specific interests of animals and the need for animals to have greater legal status. This has become a worldwide trend, with hundreds of organisations readily accessible via the internet.

Arguments Against Animal Experimentation

The ethical arguments against this kind of work are vital in civilised society. How justifiable is the common practice of deliberately inducing illness and disease in an animal in order to study some aspect of the disease or to test a drug? However, most people today who actively oppose animal experiments base their position on scientific and medical grounds.

Dr Andrew Knight, an Australian-trained veterinarian now working in the UK and one of the most widely published critics of the animal model, makes it very clear in his recent article, “Increasing the Implementation of Alternatives to Laboratory Animal Use”(AATEX, 2008, p.117):

The scientific and logistical limitations incurred by the use of animal models of humans within biomedical research and toxicity testing are substantial, and increasingly recognized.

In 1975, Richard Ryder, chairperson of the Animal Experimentation Advisory Committee of the RSPCA in the UK, published what is regarded by many as the most thorough account of animal experimentation of that time, Victims of Science. A decade later he wrote of the social, scientific and regulatory changes taking place as a result of anti-vivisectionist feeling. One of these changes was a rise in interest in the search for alternative techniques, such as tissue and organ culture, with a concomitant relaxation of scientific cynicism relating to their validity.

In his 1991 exposé on animal experiments, Why Animal Experiments Must Stop, Dr Vernon Coleman identified eight moral dilemmas to be addressed in rebutting the value of animal experiments, all of which he and others have solidly responded to, either before or after publication of his book. He also identifies eight major medical/scientific arguments for animal experimentation and provides convincing, well-documented counter-arguments.

Consider some of the evidence for three of the main arguments against animal experimentation.

Species Differences Do Exist

The jury is in on the fact that non-human and human animal biological systems are different. Their reactions not only to chemicals being tested but also to common foodstuffs can be dramatically different. That results cannot be successfully extrapolated from one to the other consistently is a strong argument and can be exemplified by these few examples, taken from Hans Reusch’s important 1982 book, Naked Empress – or the Great Medical Fraud (p.13):

Two grams of scopolamine kill a human being, but dogs and cats can stand hundred times higher dosages. A single “amanita phalloides” mushroom can wipe out a whole human family but is health food for the rabbit …. a porcupine can eat in one lump without discomfort as much opium as a human addict smokes in two weeks … the sheep can swallow enormous quantities of arsenic … morphine, which calms and anaesthetizes man, causes maniacal excitement in cats and mice. On the other hand sweet almonds can kill foxes, parsley is poison to parrots and our revered penicillin strikes other favourite laboratory animals dead – the guinea pig.

Many more similar examples of species differentiation have been cited widely in the literature.

Animal Experiments Cannot Guarantee Human Safety

The argument that animal tests followed by human clinical trials mean that drugs are safe for people to use cannot be sustained. Greek and Greek include an in-depth discussion of the “false-negative” and “false-positive” results of drug/chemical testing procedures. The first, false-negative, refers to trials where outcomes that prove safe on experimental animals are harmful, even deadly, to humans. The latter, false-positive, refers to occasions when compounds appear to be safe for humans but when animal tests are performed to validate this, the outcomes are unsafe for the animals and the compound is withdrawn. (The most famous example of this is penicillin.) The authors’ research indicates that clinical trials fail to produce the desired outcome 52–100% of the time. This represents an enormous wasted expenditure financially, in time and in research effort.

In 1999 the giant pharmaceutical company Merck was forced to announce that the anti-inflammatory drug Vioxx would have to be withdrawn because it could double the risk of stroke or heart attack. By then, millions of people had been prescribed the little yellow pill and thousands had suffered those side-effects.

In 2004, after nationwide consultation, the federal government examined the issue of xenotransplantation and decided against proceeding down this path because of the inherent risks in transplanting animal tissue and body parts into humans and the risk of zoonoses.

Alternatives to Animals Are Proving Their Value

Finally, the argument that there is no other way to do the desired research other than by using animals is fast losing ground. In 1959 Russell and Burch outlined the three Rs – refinement, reduction and replacement – in their groundbreaking work The Principles of Humane Experimental Technique, as a way of improving the conduct of animal experiments. Today in the UK, the US and Australia it is considered basic to good laboratory animal practice in scientific research, product testing and other technical procedures to follow the three Rs.

In Australia, the National Health and Medical Research Council has been responsible for the development of the Australian Code of Practice for the Care and Use of Animals for Scientific Purposes (2004) (including teaching). This code has been adopted under the animal protection legislation in each state. It is based on these three principles:

  • the refinement of techniques and procedures so as to minimise or eliminate pain, distress or other adverse effects on the animal while it is held in the research institution;
  • the reduction in the numbers of animals used by using better biometric design of experiments; and
  • replacement of animals with non-animal alternative technologies and methods wherever possible.

These principles are not optional. They are a legal requirement.

The field of alternatives to animal use is growing exponentially in both research and teaching. In 2004 it was reported that, in a program to test prediction of lethal concentrations of chemicals in human blood, rat and mouse tests were less than 65% accurate while a combination of human cell tests and computer modelling was 80% accurate. Greek and Greek report 15 non-animal methods of improving the quality and efficacy of biomedical research. Veterinary schools in the UK no longer use terminal animal laboratory classes to teach surgery but instead engage in collaborative programs with animal pounds and shelters to perform surgery on animals needing it to improve their chances of returning home. Nick Jukes and M. Chiuia’s book From Guinea Pig to Computer Mouse – Alternative Methods for a Progressive, Humane Education (2003) lists over 500 alternatives to animal experimentation in use around the world today, the manufacturers of these products, and includes several case studies of product implementation in universities and research centres.

InterNICHE, the largest organisation in the world focused exclusively on the use of animal alternatives in life science education, hosts the World Congress on Alternatives and Animal Use in the Life Sciences every second year (in 2009, Rome). This international congress attracts science educators, alternative technology producers, students and researchers.

Finally, such is the emphasis being placed by governments and sections of the scientific community around the world on finding alternatives that there exist centres dedicated to the validation of non-animal alternative methods e.g. the Johns Hopkins Centre for Alternatives to Animal Testing and the European Centre for the Validations of Alternative Methods. In Australia in 2008, the National Health and Medical Research Council undertook a call for comments on alternatives for the use of animals for scientific purposes to examine ways in which this R of the three Rs can better be resourced and implemented. One outcome of this review could be that Australia may establish a centre for the study of alternatives.


Currently, society accepts the use of animals in biomedical research and other fields. However, the fact that the practice is legal does not allay all the current, strong concerns held within and outside of the scientific community. Animal experimentation has been integral to scientific and medical research for centuries but, as the evidence cited above will indicate, may not have served those fields as well as was hoped or, more importantly, assumed. With time and new knowledge on which to base decision-making, societal attitudes change.

It seems clear today that animal experimentation raises important ethical questions about the relationships between species, about pain, suffering, deprivation, the right of one group to inflict these on another and about the responsibilities of the strong and empowered towards those weaker and less empowered. Because the practice has had some considerable longevity, it is now possible to see more fully where its contribution sits scientifically in the broad picture of scientific and medical advances. The evidence is showing that it is not as significant as once, or even still, believed.

It is up to each individual to decide where they stand in relation to the ethics of animal use in science. For people who donate to charities but are concerned about animal-based research, presents an annotated list of Australian charities whose work is not based on animal experimentation (see box above). Given the scientific and medical evidence now available, in the coming decades it will behove an informed public to demand more effective and humane research methods from the scientific and medical establishments, and the responsibility will fall to their researchers to fulfil that request.

A full list of references used in this article is available from the author on request at

Reproduced from Issues 86: Bioethics