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National Research Council (US) and Institute of Medicine (US) Committee on the Use of Laboratory Animals in Biomedical and Behavioral Research. Use of Laboratory Animals in Biomedical and Behavioral Research. Washington (DC): National Academies Press (US); 1988.

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Use of Laboratory Animals in Biomedical and Behavioral Research.

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Executive Summary

The use of animals in scientific research has been a controversial issue for well over a hundred years. The basic problem can be stated quite simply: Research with animals has saved human lives, lessened human suffering, and advanced scientific understanding, yet that same research can cause pain and distress for the animals involved and usually results in their death. It is hardly surprising that animal experimentation raises complex questions and generates strong emotions.

Animal experimentation is an essential component of biomedical and behavioral research, a critical part of efforts to prevent, cure, and treat a vast range of ailments. As in the past, investigators are using animals to learn about the most widespread diseases of the age, including heart disease and cancer, as well as to gain basic knowledge in genetics, physiology, and other life sciences. Animals are also needed to combat new diseases, of which acquired immune deficiency syndrome (AIDS) is currently the most prominent example. At the same time, behavioral researchers are drawing on animal studies to learn more about such major causes of human suffering as mental illness, drug addiction, and senility.

The recognition that animals are essential in scientific research is critical in making decisions about their use, but these decisions are also made in the broad context of social and ethical values. In this report, the committee addresses these issues and examines how and why animals are used in research and how society oversees that research.

Patterns of Animal Use

Data about the numbers and species of animals used for scientific experimentation in the United States come primarily from two sources: the National Research Council's Institute for Laboratory Animal Resources (ILAR) and the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS). Though the information from both of these sources is incomplete, it provides a picture of the magnitude of animal experimentation in the United States. In 1983, an estimated 17 to 22 million animals were used for research, testing, and education in the United States. In this case, ''animal'' includes all vertebrates—namely, mammals, birds, reptiles, amphibians, and fish. The majority of animals used—between 12 million and 15 million—were rats and mice. These quantities are a small fraction of the total of over 5 billion animals used annually for food, clothing, and other purposes in the United States.

A significant portion of the laboratory animals used each year are involved not in research but in testing. Research and testing are not always separable, but testing generally entails the use of animals, primarily rats and mice, to assess the safety or effectiveness of consumer products such as drugs, chemicals, and cosmetics.

The data concerning the numbers of animals used in testing are not complete. Various sources estimate that anywhere from several million to more than half of the approximately 20 million animals used for research and testing in the United States are used for testing. In contrast, the use of animals in education is relatively small (i.e., only an estimated 53,000 animals are used per year in teaching in medical and veterinary schools) and has been declining in recent years.

In general, the data concerning animal use in the United States must be viewed as uncertain. The Office of Technology Assessment has concluded that it is not even possible to tell from the existing data whether the total number of animals used each year is increasing or decreasing. A survey now being planned by ILAR, the fourth in a series of ILAR surveys conducted since 1962, will provide some of this information.

Animal research encompasses a wide range of biomedical and behavioral experiments. One field of behavioral research entails observing animals in colonies that simulate their natural environments. Other animals undergo medical procedures such as surgery to gauge the effectiveness of new techniques. Some are exposed to toxic substances until death or disability results. Others are killed immediately to obtain an essential organ or tissue for further studies. Although long-term survival is sometimes the goal of animal experimentation, most research animals are humanely killed at some point during the course of the research.

Benefits Derived from the Use of Animals

The use of animals in biomedical and behavioral research has greatly increased scientific knowledge and has had enormous benefits for human health. For example, in the United States, animal experimentation has contributed to an increase in average life expectancy of about 25 years since 1900. A few examples give an indication of the breadth and variety of these contributions.

  • Animals have been used to study cardiovascular function and disease since the early 1600s. Heart-lung machines, which have made open-heart surgery possible, were developed with animals before being used with humans. More than 80 percent of all congenital heart diseases that were formerly fatal can now be cured by surgical treatment based on animal experiments. Similarly, a wide variety of surgical techniques and drug treatments, which have extended life for millions of Americans, were first perfected in animals.
  • Studies of the biology of transplantation in animals have made it possible to transfer organs between people. Some 30,000 Americans now alive have transplanted kidneys, which free them from the laborious and uncomfortable dialysis treatments once needed to keep them alive. Other Americans are now alive because of transplanted hearts or livers, or have had their lives immeasurably improved because of skin or cornea transplants. Basic research on transplantation has also contributed greatly to the understanding of immunology, with wide ramifications for the treatment of many diseases.
  • Animal research shed light on the nature of polio and has helped to nearly eliminate the disease from the United States. In the early 1900s, researchers succeeded in transmitting the polio virus to monkeys for the first time. In following years, investigators tested various altered or inactivated forms of the virus in monkeys until strains were found that could immunize the monkeys without giving them the disease. This work led to human vaccines that have reduced the number of cases of paralytic polio in the United States from 58,000 in 1952, at the height of one epidemic, to 4 in 1984.
  • Many clinically useful methodologies were first tested on animals before being used with humans. Examples include computed axial tomographic (CAT) scans and magnetic resonance imaging (MRI).
  • Animal studies have been essential in probing the functions of the brain in health and disease. Investigators have used animals to understand movement (and the movement dysfunctions caused by such diseases as epilepsy and multiple sclerosis), vision, memory (including the severe memory loss that occurs in 5 percent of persons over the age of 65), drug addiction, nerve cell regeneration, learning, and pain.

The use of animals is important if biomedical research is to continue to lead to the understanding and amelioration of diseases such as cancer, diabetes, and uncontrolled infectious diseases. It will also be essential in efforts to understand and control newly emergent human diseases. For example, researchers have identified viruses in monkeys and other animals that cause diseases in those species similar to AIDS. These animals can therefore act as model systems for the human disease, allowing investigation of possible treatments and vaccines.

Animal research does not only benefit humans. Much animal research also benefits animals, either directly because animal health is the subject of research or indirectly because the same procedures and treatments used in humans can be used in animals. Most of the animals that benefit from this research are domesticated and therefore assist humans in some way—as sources of food and fiber, for instance, or as pets and companions. Vaccines, antibiotics, anesthetics, and other products have improved the lives of countless animals.

Alternative Methods in Biomedical and Behavioral Research

Scientists have been and are searching for alternative methods to the use of animals in biomedical and behavioral research for a variety of reasons, including an interest in the welfare of animals, a concern for the increasing costs of purchasing and caring for animals, and because in some areas alternative methods may be more efficient and effective research tools. In current usage, the term "alternative methods" includes replacements for mammals, reductions in the use of animals, and refinements in experimental protocols that lessen the pain of the animals involved.

One way to reduce the use of mammals is to modify experimental protocols so that fewer of them are needed. In the field of testing, for instance, methods have been found to assess toxicity using fewer mammals than were once thought necessary. In addition, in some experimental situations, features of mammals can be modeled by nonmammalian vertebrates (birds, reptiles, amphibians, and fish), invertebrates, plants, organs, tissues, cells, microorganisms, and nonbiological systems. For example, research conducted on the fruit fly Drosophila has led to understandings in genetics that apply to all living things, and mathematical models can increase the effectiveness of experiments by defining variables and checking theories, thus making experiments on biological systems more effective and economical. Finally, experimental protocols can be refined to reduce the pain and suffering experienced by laboratory animals. These approaches are all referred to as alternatives.

The search for alternatives to the use of animals in research and testing remains a valid goal of researchers, but the chance that alternatives will completely replace animals in the foreseeable future is nil. Nevertheless, successes have occurred in reducing the numbers of animals used, in developing nonmammalian models, and in refining experimental protocols to reduce the pain experienced by animals, and work continues in this area.

Recognizing the above, the committee recommends that:

  • Research investigators should consider possible alternative methods before using animals in experimental procedures.

To enable researchers better to consider alternatives, it is important that they have access to relevant information. The committee therefore recommends that:

  • Databases and knowledge bases should be further developed and made available for those seeking appropriate experimental models for use in the design of research protocols.

Furthermore, although the committee's work has focused mainly on research, it recommends that:

  • Federal regulatory agencies should move rapidly to accept tests—as such tests become validated—that reduce the number of vertebrates used, insofar as this does not compromise the regulatory mission of an agency and protection of the public.

Regulatory Issues

The laws and regulations governing animal research reflect the broad ethical considerations surrounding the use of animals by humans. The most important federal law affecting animal research in the United States is the Animal Welfare Act. Passed in 1966 and amended in 1970, 1976, and 1985, the act sets minimum standards for handling, housing, feeding, and watering laboratory animals and establishes basic levels of sanitation, ventilation, and shelter from temperature and weather extremes. The law covers those warm-blooded animals designated by the secretary of the U.S. Department of Agriculture, the overseer of the Animal Welfare Act. At present, this includes dogs, cats, nonhuman primates, rabbits, hamsters, guinea pigs, and marine mammals, but not rats, mice, birds, and farm animals used in biomedical research—although rats and mice account for about 85 percent of the animals used in research, education, and testing.

The most recent amendments to the Animal Welfare Act, which took the form of the Improved Standards for Laboratory Animals Act of 1985, added several important provisions to the law. The law requires investigators to consider alternative methods that do not involve animals and to consult with a veterinarian before beginning any experiment that could cause pain. It also requires that dogs receive proper exercise, that primates be provided with environments that promote their psychological well-being, and that all animals used receive adequate presurgical and postsurgical care and pain-relieving drugs. These amendments also require that each registered research facility appoint a committee to monitor animal research in that institution. These committees must include a veterinarian and a person unaffiliated with the research facility to represent the community's interests in animal welfare. Committee members must inspect the facility's animal laboratories twice a year and report deficiencies to the institution for correction. If the deficiencies are not corrected promptly, the U.S. Department of Agriculture must be notified for enforcement, and any funding agency must be informed so that it can decide whether to suspend or revoke grants or contracts to the violator.

A second long-standing, important document affecting animal research in the United States is a product not of the federal government but of the scientific community. In 1963, the Animal Care Panel released the Guide for Laboratory Animal Facilities and Care. The Guide has been revised five times since then by ILAR, most recently in 1985, and has been renamed the Guide for the Care and Use of Laboratory Animals to reflect its broadened scope. Its purpose is to assist investigators and institutions in caring for and using laboratory animals professionally and humanely. It is written in general terms so that it can be used by the wide variety of institutions that conduct experiments using animals.

A number of other government agencies and private organizations have drawn on the Guide in establishing standards for animal research. The 1985 Health Research Extension Act, which reauthorized funding for the National Institutes of Health (NIH), requires that researchers receiving funding from NIH adhere to the standards of the Guide. In 1986, the Public Health Service (PHS)—which includes NIH, the Food and Drug Administration, the Centers for Disease Control, and the Alcohol, Drug Abuse, and Mental Health Administration—released the most recent revision of its policy statement on the humane care and use of laboratory animals. This, too, requires compliance with the Guide. An Interagency Research Animal Committee incorporated the Guide by reference in its 1985 "U.S. Government Principles for the Utilization and Care of Vertebrate Animals Used in Testing, Research, and Training." On the nongovernmental side, the American Association for Accreditation of Laboratory Animal Care uses the Guide in evaluating the animal facilities of institutions seeking accreditation.

In addition to requiring compliance with the Guide, the PHS policy statement and 1985 Health Research Extension Act include several other important statutory and regulatory changes. They require that each institution receiving funds from PHS maintain an Institutional Animal Care and Use Committee (IACUC) to monitor animal research. As with the committees required by the Animal Welfare Act, each IACUC must include one veterinarian and one individual not affiliated with the institution. Investigators who plan to use animals must submit their research protocols to these committees, including a justification for the use of a particular kind of animal and a demonstration that they have considered methods that do not use animals.

The use of animals for research, testing, and education is also regulated in other ways in the United States. For example, the Food and Drug Administration and the Environmental Protection Agency have established Good Laboratory Practices (GLP) regulations that affect the use and care of animals.

Even with this abundance of regulatory activity, self-regulation is the most important determinant of humane treatment of animals. Professional societies have set up guidelines to be followed by their members. In addition, many individual institutions—governmental, academic, and private—have established policies governing animal experimentation and testing. Many institutions now provide information and instruction to animal users on the proper care and handling of research animals. Most important are individual investigators; under the review of their institutional animal committees, they ultimately have the greatest control over and responsibility for how an animal will be cared for and used. At the same time, most scientists acknowledge the need for regulations to set minimum standards and provide for public accountability.

Although humane care and use of laboratory animals characterize the scientific community, there have been from time to time some members of this community who have been found to care inadequately for their animals. The committee believes that the mistreatment or mishandling of animals is not acceptable. Maltreatment and improper care of animals used in research cannot be tolerated, and individuals responsible for such behavior must be subject to censure. Without such punishment, the continued use of animals by all scientists is threatened, as more regulations and restrictions are imposed by legislative and regulatory authorities in response to their perception that scientists who commit abuses are not punished.

Many scientists believe, however, that present regulatory procedures can in some instances be disruptive, in that they may decrease efficiency, increase costs, and slow progress. For instance, obtaining preliminary approval of all research protocols does delay some experiments. On the other hand, protocol review can help the researcher when it provides an opportunity for the scientist's peers to offer advice and assistance. This advice may result in a better-planned experiment that not only improves animal care and minimizes animal pain but also leads to more instructive results. In any case, more extensive regulations may have contributed to the increased expense of animal research, which constrains the research that can be done.

The requirement that investigators strictly comply with the Guide for the Care and Use of Laboratory Animals has also raised difficulties. The 1985 Health Research Extension Act essentially imparts the force of law to the Guide, but the Guide was not written to be a legal document. It was designed to provide for flexibility in interpretation, guided by professional judgment. As such, it has served the community of individuals using laboratory animals well in the more than 20 years since it was first published. Because it is now being used to set minimum standards for inspection, it may in some respects be too rigidly interpreted, as in the requirement for multiple separate areas and rooms for performing aseptic surgery. If the Guide is to act as law, it should be carefully examined and redrafted as needed to ensure that its language satisfies the intent, as distinct from the letter, of the law.

In the general area of regulation, the committee recommends the following:

  • No additional laws or regulatory measures (except the regulations required by the Improved Standards for Laboratory Animals Act of 1985) affecting the use of animals in research should be promulgated until, based on experience, a careful accounting of the effects of the application of the present body of laws, regulations, and guidelines has been made and evidence of the need for more regulation is available.
  • A mechanism should be established for ongoing review of the regulatory framework of federal agencies for animal experimentation. It is essential that research scientists who must abide by this regulatory framework be prominently involved in its assessment. Specifically, the Guide for the Care and Use of Laboratory Animals should be reviewed as soon as possible to determine whether revisions are necessary due to new information.
  • Federal standards developed by different agencies for the care and use of laboratory animals should be congruent with each other.
  • Sufficient federal funds should be appropriated for the inspections required for the enforcement of the Animal Welfare Act.
  • Sufficient federal funds should be appropriated for maintenance and improvement of animal facilities to allow individuals and institutions to conduct animal research in compliance with government policies, regulations, and laws. It is important that such funds should be added to ongoing research support.

Use of Pound Animals

One of the most controversial areas in the current debate involves the use of impounded dogs and cats. The emotions engendered have resulted in the passage of laws by a number of political jurisdictions that prohibit or restrict the release of impounded animals for use in research. These laws create a dilemma: the impounded animals are not released for use in research but are killed by the pound or shelter if not claimed. Each year more than 10 million such animals are destroyed at pounds or shelters, whereas fewer than 200,000 dogs and cats are released from pounds and shelters to scientific establishments for use in research—less than 2 percent of the number that are destroyed.

A prohibition against the use of pound animals also means that more animals are used each year. Instead of using one of the 10 million pound animals that will be destroyed, different animals are bred for use in research.

Whether a pound animal or a "purpose-bred" animal is the appropriate research model depends on the needs of the experiment. Pound animals are seen as having varied genetic backgrounds. In some experiments the genetic variability, because it is much like that found naturally in humans, is an advantage; in other cases it is necessary to know the genetic background of the animal, requiring an animal bred for research. For other experiments it may be necessary to use purpose-bred animals because the health history, physiological status, and age of pound animals are not well enough known to ensure that conditions present in the animals will not interfere with conduct of the experiment.

Twelve states have passed laws that prohibit the release of impounded animals for use in research. In 11 of these states, researchers can use animals impounded in other states, which are legally transported across state lines by dealers. In Massachusetts, a new law that went into effect in 1986 prohibits researchers from using any animals from pounds, no matter where those animals were impounded.

A prohibition against the use of pound animals inevitably increases the costs of animal research because the cost of an animal from a dealer is greater than the cost of a pound animal. If the impounded dogs used each year in research were not available, a substantial additional cost would be incurred from buying replacement dogs from dealers.

In addressing the use of pound animals:

  • The committee unanimously recommends that pound animals be made available for research in which the experimental animals are used in acute experiments (i.e., in which the animals remain anesthetized until they are killed). While a majority of the committee supports the appropriate use of pound animals in all experiments, a minority opposes the use of pound animals for chronic, survival experiments.

American society is a pluralistic society in which public policy takes into account many different perspectives. No single ideology or theology governs people's ways of thinking. Similarly, decisions in the United States do not arise unilaterally from authorities. They reflect a consensus within society, as expressed through people's elected representatives.

Some people will continue to contend that animal research should be eliminated. The committee rejects such a view. Indeed, the committee concludes that:

  • Humans are morally obliged to each other to improve the human condition. In cases in which research with animals is the best available method to reach that goal, animals should be used.

The committee also recognizes that:

  • Scientists are ethically obliged to ensure the well-being of animals used in research and to minimize their pain and suffering.

The committee affirms the principle of humane care of all animals used in research and recommends that:

  • All those responsible for the care and use of animals in research should adhere to the principle that these animals be treated humanely.
Copyright © National Academy of Sciences.
Bookshelf ID: NBK218267

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