Animal Experimentation

I

Introduction

Animal Experimentation, the use of animals under controlled laboratory conditions for a variety of scientific and medical purposes. Scientists use laboratory animals to investigate biological processes in humans and animals; to study the causes of diseases; to test drugs, vaccines, and surgical techniques; and to evaluate the safety of chemicals used in pesticides, cosmetics, and other products.

In many cases, scientific and biomedical research can be performed on laboratory cultures consisting of specific cells or tissues, or on simple life forms such as bacteria. Some research, however, is better conducted by studying the more complex responses of an animal. Many animals function essentially like humans, and thus provide the best models for experiments on fundamental processes such as breathing, eating and digesting food, and reproducing. Some animals suffer from the same diseases as humans do, with immune systems that respond similarly to disease-causing agents such as viruses and bacteria. Animals also carry a number of genes that are identical to human genes, with information for similar traits. Given these similarities, scientists have been able to learn much about the human body by studying animals.

The practice of experimenting on animals goes back many centuries. As early as the 2nd century ad, Roman physician Galen experimented on pigs and apes to demonstrate that veins carry blood, not air, as had been believed. In the early 1600s English physician William Harvey studied diverse animals such as worms, insects, fish, and frogs, providing pioneering insights into the principle by which blood circulates in the body. Use of animal experimentation increased significantly in the 1800s, reflecting the rapid development of science during that century. Among other investigations, scientists used animals to explore the major body organs, the function of the nervous system, and the role of microorganisms in causing disease.

Animals continue to play an essential role in research—between 18 and 22 million animals are used yearly in the United States. About 90 percent of these animals are rats, mice, and birds. Other experimental animals include primates, rabbits, pigs, hamsters, guinea pigs, dogs, and cats. The total number of animals used in experiments in the United States is falling, however. According to the United States Department of Agriculture (USDA), the use of primates, rabbits, pigs, hamsters, and guinea pigs fell from 2.1 million in 1985 to approximately 1.4 million in 1995, a decline of roughly 33 percent. Since the 1970s, the use of dogs and cats has declined by about 50 percent. Animal use has also declined in the United Kingdom and in Europe.

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II

Regulating Animal Experimentation

At least in part, this decrease reflects society’s changing views about animal rights. Animal experimentation has long drawn outcry and protest from people committed to the protection of animals. In the 1970s the animal rights movement gained new momentum and visibility, particularly with the 1975 publication of the book Animal Liberation, by Australian philosopher Peter Singer, which called animal experimentation morally indefensible. In many incidents during the 1970s and 1980s, protest took the form of late-night raids on research facilities. Animal rights activists broke into laboratories, freed animals, and destroyed data and equipment. The total damage from raids between 1985 and 1990, according to the Association of American Medical Colleges, exceeded $3.5 million, and universities and research facilities spent millions more on increased security.

Media coverage of these raids—and in some cases, evidence of serious animal mistreatment exposed by activists in some cases—brought animal experimentation into wider public view. Animal rights groups pressed for changes in the laws that govern the protection of lab animals. The main federal law pertaining to animal research is the Laboratory Animal Welfare Act. This law was first passed in 1966, partly because of reports about sales to laboratories of stolen pets. The act initially required that certain animals used for research—including dogs, cats, primates, rabbits, hamsters, and guinea pigs—be obtained via legal means and given humane care. In 1970 the Animal Welfare Act was amended to require that laboratory animals receive painkilling drugs whenever appropriate; in 1985 the act was amended again, requiring that each research facility receiving federal money create a special committee to oversee animal research. Furthermore, resources must be devoted to the physical and emotional well-being of lab animals. The 1985 amendments also require federally funded researchers to consider alternatives to animal use.

III

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 Government Accountability 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.

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