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BENEFITS OF ANIMAL EXPERIMENTATION

Proponents of animal experimentation point to hundreds of years of medical advances made possible by research on animals. Treatments for heart disease provide just one example, including open-heart surgery, in which circulatory functions are temporarily controlled by a heart-lung machine; coronary bypass to improve blood flow to the heart muscle; and valve replacement of a defective heart valve. Techniques and equipment for kidney dialysis were also developed through animal experimentation. More than 30 drugs for treating cancer, as well as anticancer radiation therapies, were first tested on rats and mice. Vaccines for diphtheria, measles, smallpox, and many other previously feared diseases were developed through animal research. Organ transplants, blood transfusions, microsurgery to reattach severed limbs—these and other procedures that save thousands of lives annually—were made possible by work on animals. And not just humans, but dogs, cats, and other domestic and farm animals have benefited from such research, with the development of treatments for distemper, rabies, anthrax, and other diseases of animals.

Modern biotechnology is providing still more opportunities for advances with the development of transgenic organisms, such as mice that are specially bred to carry selected human genes. Transgenic organisms permit researchers to investigate genetic causes of cancer and other diseases. In other promising work with spinal cord injury and paralysis, neurobiologists experimenting on rats and mice are investigating ways to repair nerve tissue and restore movement. Animals are also being used to seek cures for today’s most pressing diseases, including Alzheimer’s disease and acquired immunodeficiency syndrome (AIDS).

            IV    REASONS FOR OPPOSITION

Opponents argue that animal research is cruel, immoral, and unnecessary. “The question,” wrote English philosopher Jeremy Bentham, discussing animals used in experiments, “is not can they reason, nor can they talk, but can they suffer?” More recently, Peter Singer, in Animal Liberation, argues that all species that can feel pain and suffering—animal as well as human—deserve equal consideration. Many people believe that animals are no less complex than humans in their capacity to feel emotions—and to suffer pain. In this view, the infliction of discomfort, pain, suffering, and death on laboratory animals, which are incapable of giving consent to experimental procedures, is purely wrong.

Opponents also dispute the scientific validity of results obtained from animals. Many observers question whether data obtained from animals can be reliably applied to humans. They argue that physiological differences between animals and humans make them unsuitable as experimental models. Animal rights activists cite figures of the United States General Accounting Office (GAO) showing that 52 percent of the new drugs marketed between 1976 and 1985 caused adverse reactions that were not predicted by animal studies. Opponents of animal experimentation also point out that experimental animals are under great stress, often confined in small cages or held in special equipment designed to restrict movement. The stress created by confinement, and by repeated handling for experimental procedures, may significantly alter an animal’s physiological functioning, rendering any experimental observations meaningless.

Researchers in labs worldwide currently experiment with a variety of alternatives, such as in vitro methods, which use cell and tissue cultures in place of whole animals. One such test-tube method, designed to replace rabbits in evaluating the skin-irritating properties of new chemicals, has already won approval from the United States government, which requires extensive testing before chemicals can be used in commercial products. Another promising avenue involves developing more sophisticated methods of statistically analyzing data. Such "data-mining" measures mean that fewer animals are required for tests, or that animals are completely unnecessary. Powerful computer programs, designed to imitate biological functions and demonstrate how a living body reacts to toxic chemicals or disease pathogens, are yet another alternative.

Animal rights activists representing the extreme view support a complete ban on animal experimentation in favor of alternative methods. Despite increased interest in and success with alternatives, however, many scientists believe that there is no substitute for the complex response of a whole animal. In their opinion, animal research is vital for continued biomedical progress. The complexities of the animal experimentation debate are certain to remain a topic of discussion for years to come.