Animal Testing

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Animal Testing

In order to more completely understand biology, researchers sometimes conduct experiments on animals. Animal experimentation has a lengthy and productive history in biological research, especially in biomedicine. For example, the organ transplant pioneer Thomas E. Starzl conducted his early surgical transplantation experiments on dogs in the 1960s before successfully attempting them on humans. Psychiatrist John Cade made the discovery that lithium aids manic-depressive patients by experimenting with guinea pigs in the 1940s. Today, many animals are used for a variety of purposes in experimental science. While some studies use primates or other animals, over 90 percent of studies involve mice and rats, for experiments from immunological projects to cancer research. While animal research is enormously important to the advancement of biomedical science, some activists feel that animals should not be used as experimental subjects.

The Animal Welfare Act (1966)

To ease undue suffering inflicted on these experimental subjects, scientists William Russell and Rex Burch published The Principles of Humane Experimental Technique in 1959, wherein they described the three Rs: Reduce animal experiments, Refine them to make the experiments less unpleasant, and Replacement of animals by different techniques. Their concern over the "distress" suffered by animals, along with more general feelings of humaneness, led to the creation of the Animal Welfare Act by the federal government in 1966. The act was designed to protect animals that might be test subjects by requiring proper care of them, and it sets forth a list of guidelines researchers must comply with. For example, it stipulated that the animals must receive adequate veterinary care. In 1970, the act expanded from protecting dogs, cats, primates, guinea pigs, rabbits, and hamsters to "all warm-blooded animals." Significantly, the act exempts mice, rats, and birds from the protection it confers on other species. The act originally applied largely to pet dealers but with subsequent amendments grew to include, and even focus on, scientific research animals.

As the act forced scientists to care more properly for their test subjects (and with consistently healthy animals, enjoy more predictable and complete experimental results), a movement began in the 1970s to stop the use of animals in experimental science altogether. In 1975, philosopher Peter Singer published Animal Liberation, in which he argued that all animals capable of perceiving pain were moral equals to human beings. In subsequent years, some animal rights activists (who, willing to cede moral rights to animals, must be differentiated from animal welfare activists, who only wish to see animals treated humanely) have taken increasingly severe stances on the subject of animal research. In 1986, the then-director of People for the Ethical Treatment of Animals, Ingrid Newkirk, asserted to the Washingtonian that "animal liberationists do not separate out the human animal, so there is no rational basis for saying that a human being has special rights. A rat is a pig is a dog is a boy. They're all mammals." She also likened the deaths of broilerhouse chickens to those of Jews during the Holocaust. Extreme animal rights activists have targeted scientists with terrorist or destructive acts in an effort to stop research. In particular, behavioral scientists and addiction researchers receive a lot of attention from activists because of the use of live primates in these fields.

Ethics vs. Research Imperatives: Finding a Compromise

Many activists protest cosmetics research rather than biomedicine, as some consider makeup to be less crucial to human existence than, say, cancer research. Additionally, not all animal rights activists are terrorists or extremists. For example, the Johns Hopkins Center for Alternatives to Animal Testing promotes the 3 Rs wherever it can. While many alternative suggestions for scientists may not be feasible, no scientist is so cruel as to want animals to suffer unnecessarily. However, for certain experiments, there are many advantages to using animals over other methods. The creation and maintenance of tissue and/or organ cultures in a test tube to simulate biological systems is extremely difficult, and using a live animal instead makes studying such systems possible. For addiction research, it is impossible to gain behavioral data without working with some sort of living animal. Many drug studies require the observation of treated animals, as do experiments on blood vessels (such as angioplasty research) and immune system tolerance (for investigations of transplantation biology). While many activists call for the use of computer simulations as an alternative to animal research, such simulations rarely work or reflect reality.

This is not to say that animals are required for every study. There are plenty of in vitro (test-tube) tests for the toxicity of certain compounds. Using human cells grown in culture has proved to be particularly accurate in this regard. For educational purposes, computer simulations can be as effective as real-life dissections. Only 70 percent of agents that cause cancer in mice will cause it in rats, suggesting that comparisons across species are not always valid: conclusions reached by studying animals may not be true for humans. In 1990, David Wiebers and colleagues from the Mayo Clinic reported that of twenty-five drugs found to reduce damage following strokes in animals, none proved effective in human trials. There are many instances in which animal studies may not work, simply because animal organ systems and cellular structure differ from humans.

Knowledge can be gleaned from epidemiological studies, or studies that follow the spread of disease, as an alternative. Clinical study, or the investigation of disease and how it manifests itself in a human population, can also offer insights to biological questions that cannot be answered with the use of animals. Some diseases, like HIV, rely heavily on these tactics because the animal simulations are too different or unwieldy. While studies of the transmission of Simian Immunodeficiency Virus (SIV), a close relative of HIV, in nonhuman primates can be useful, SIV is still a different disease.

It is worth noting that the animal rights movement has gained momentum at a time when there are far fewer Americans living on farms. A familiarity of animals as house pets, and not dinner, may have contributed to the movement. Animals may prove invaluable to certain studies. Moral considerations aside, the practical constraints of a given study might dictate that the use of animal subjects will not answer the question. Explorations of alternatives can be a good idea, because they may produce experiments that more closely mimic the human response to a treatment. And, after all, a more perfect model system is good news for everybody.

see also Animal Rights; Bioethics.

Ian Quigley


Barnard, Neal D., and Stephen R. Kaufman. "Animal Research Is Wasteful and Misleading." Scientific American 276 (February 1997):80-82.

Botting, Jack H., and Adrian R. Morrison. "Animal Research Is Vital to Medicine."Scientific American 276 (February 1997):83-85.

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Animal Testing

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