It is important to bear in mind that no figures are available to determine the precise number of animals used in research and testing, largely because there are no reporting requirements on mice and rats, the animals used in the overwhelming majority of experiments (95 to 97%), because they are not protected under the Animal Welfare Act (AWA). The best available estimates, however, put the total number of animals used annually in the United States at 100 million. Worldwide, an estimated 192.1 million animals are used every year for scientific purposes.
The top 10 animal testing countries in the world are estimated to be China (20.5 million), the United States (15.6 million), Japan (15.0 million), Canada (3.6 million), Australia (3.2 million), South Korea (3.1 million), the United Kingdom (2.6 million), Brazil (2.2 million), Germany (2.0 million) and France (1.9 million).
A number of legal challenges have been made to include rats, mice, and birds under the AWA’s coverage. To date, these efforts had been only moderately successful, gaining support in the court system only to be obstructed legislatively or with the USDA failing to fulfill its obligations. However, in 2020, as a result of a lawsuit, the USDA is now subject to a court order to complete rulemaking to protect birds, as required by the AWA. As of February 22, 2022, the proposed rule has been published on the Federal Register and is open to public comments until April 25, 2022.
History of Lab Animal Use
Vivisection (the act of cutting into a living animal, usually for the purpose of physiological and pathological knowledge) has been practiced since ancient Greek and Roman days, when live animals were cut open without anesthesia to study bodily functions. Similar practices continued throughout the Middle Ages, as people believed that man was the center of the universe and, therefore, that he could do anything he wanted with other animals. Yet during the second half of the 1600s, following a dramatic rise in animal experimentation during the Renaissance, some philosophers began to object to the suffering of animals used for scientific research. Throughout the 1700s and early 1800s, this trend continued. The first organized protest against vivisection was led by British women in Florence, Italy in 1863, and the first Cruelty to Animals Act, mandating the use of anesthetics during vivisection, was passed in England in 1876.
In the mid-nineteenth century, however, the publication of Charles Darwin’s book Origin of Species increased scientific interest in species evolution and strongly reinforced the idea that animals could serve as models for humans in the study of biology and physiology. Additionally, Claude Bernard’s Introduction to the Study of Experimental Medicine popularized the idea of vivisection as the predominant mechanism for scientific research. During this period and through World War I, animal research was established as a significant method of laboratory investigation. This trend continued into the mid-twentieth century. Another increase in laboratory animal use came after World War II, when the government began providing a significant amount of funding for research.
In 1966, Congress passed the first legislation aimed at regulating the care and use of animals in U.S. laboratories. Called the Laboratory Animal Welfare Act, it was enacted following a rise in public concern over the mistreatment of lost and stolen cats and dogs by laboratory animal dealers. Later strengthened through three major revisions and renamed the Animal Welfare Act, it now covers animals not only in laboratories but also in zoos, circuses, and aquaria, in addition to overseeing animal transportation and animal fighting.
Animal research reached its highest level in the United States in the mid-1980s following decades of public support for scientific research of all kinds. During this same time, animal activists were able to pressure cosmetics companies to reduce or eliminate animal use in the testing of their products. The development of new mechanisms for product safety testing that were not animal-based opened the door for this change. In the decade that followed, the number of animals used in laboratories for research, testing, and education began to decline—some say by as much as 40-50%. Today, however, the use and maintenance of genetically engineered animals (those that have had their genetic code altered to produce a specific result), especially rats and mice, has greatly increased the number and suffering of laboratory animals.
Purpose of Lab Animals
Animals are used in laboratories today for one of three main purposes: biomedical research (testing drugs and vaccines); testing consumer products (cosmetics and cleaners); and for education (medical and veterinary school).
Biomedical Research: A study published in Scientific Reports in January 2021 estimates that more than 111 million mice and rats are used annually in U.S. biomedical research, a figure that represents more than 99% of all lab animals.
Biomedical research is based on the idea that animals are similar enough to humans to serve as “models” for the study of human organ systems. Discoveries credited by scientists to the use of animals in research include penicillin, insulin, the polio vaccine, chemotherapy for childhood leukemia, hip replacement and heart bypass surgery. However, critics of biomedical animal research, including many scientists, challenge the assumption that animals are appropriate models for humans, pointing to failures in extrapolating from one species to another. They cite examples of animal research that delayed the discovery of a cure or misled scientists into believing in the safety of a drug or vaccine that turned out to be harmful to humans.
Testing Efficacy of New Drugs and Vaccines: Most commonly used animals in laboratories to evaluate the safety and effectiveness of new drugs and vaccines are mice, rats, rabbits, and dogs. Before new compounds can even be tested on small groups of humans, they are first tested extensively on animals. Upwards of 95% of drugs shown to be safe and effective in animals fail in human trials.
Critics of animal use in drug and vaccine development raise concerns about the possibility of rejecting compounds that might prove to be miracle drugs in people even though they are toxic to certain animals. If penicillin had been tested only in guinea pigs, they say, humans might never have benefited from this life-saving antibiotic. Additionally, the benefit of a treatment to humans is not fully known or able to be reliably measured until it is tested clinically on a human population. Thus, despite having been tested on and costing the lives of thousands of animals (and likely costing millions of dollars), the ultimate efficacy of a drug or vaccine is still largely unknown until it is tested on a human population.
Consumer Product Safety Testing: U.S. government agencies require an extensive array of animal tests to assure the safety of items such as shampoo, food packaging, and household cleaners. These products are tested for their toxicity to the eyes and skin, for their potential to cause internal organ damage, and for their safety for use by pregnant women. In some cases, animal tests are specifically required by a federal regulatory agency. In other cases, only the “best available” safety information is requested. Many American regulatory agencies, however, still believe that traditional animal tests are the “best available.”
While there is still much progress to be made, many manufacturers have dramatically reduced their reliance on animal use in product safety testing in the last two decades. Two crucial components of this change have been the sharing of information about the safety of ingredients and product formulations, as well as the utilization of computers in facilitating searches of databases containing this information. While truly reliable figures are not available, it is estimated that of all of the animals used to test the safety of personal care products in the U.S., only 5% are protected through the AWA.
Animals in Education: Medical schools historically used animal labs for education, but they have made great progress in recent years with all medical schools in the U.S. having now ceased the use of animal laboratories. Some veterinary schools still use live animal labs in their educational programs and many of the dogs used are anesthetized healthy dogs that are used for terminal surgical training. Most veterinary schools, however, have phased out of terminal surgical training and are instead providing their students with surgical experience on organ models, in spay/neuter clinics, or via Educational Memorial Programs (EMPs) wherein pet owners can donate the bodies of their deceased animals to veterinary schools for surgical and anatomical training. Further, new technology is being developed. For example, a biotech company called SynDaver released a synthetic canine model that mimics the functions of a living dog. It is anticipated that this synthetic model will revolutionize veterinary surgical training.
In addition to laboratory animals used in higher education, millions of additional animals are killed each year for use in dissection classes in elementary and secondary schools. Frogs are most common, but cats, fetal pigs, rats, and snakes are also used, despite the availability of a wide variety of alternatives that have been demonstrated to provide students with equivalent learning experiences. These alternatives include interactive programs, virtual reality programs, as well as non-living animal models, which can be used instead of live animals to study anatomy. As of 2020, 22 states have upheld (through state law, resolution, or Board of Education policy) a student’s right to choose humane alternatives to dissection without being penalized.
Sources of Lab Animals
There are three primary sources of laboratory animals: wild, purpose-bred, and stray or unwanted animals. Most are purpose-bred—that is, they are bred in a laboratory specifically for use in research, testing, or education. The federal government identifies those who breed and sell these animals as Class A animal dealers.
Random source dealers, or Class B dealers, also supply animals to laboratories. These dealers are those licensed to collect laboratory animals from “random sources:” stray or otherwise unwanted dogs, cats, and other animals off the streets; from animal auctions; and from municipal animal control and local animal shelters. While “pound seizure,” the practice of acquiring laboratory animals from pounds and shelters, is prohibited by law in some states (in 1986, Massachusetts was the first state to make this practice illegal), other states allow for animals in pounds to be turned over to research laboratories, and Oklahoma even requires this. Class B dealers are licensed and regulated by the USDA.
Trends show that the demand for laboratory animals acquired from random sources is on the decline. In 2015, three Class B random-source dog and cat dealers were licensed to sell animals for experimentation in the United States. That number is down from 11 in 2009 and is a significant reduction from the early 1990s, when there were more than 100 such dealers selling dogs and cats. A 2009 report by the National Academies of Sciences (see below) concluded that animals from random-source dealers are not necessary for National Institutes of Health (NIH) supported research. As a result, the NIH has since phased out funding for research that uses cats and dogs from Class B dealers.
Although there are only a few random-source Class B dealers still licensed in the U.S., they remain a concern. Kenneth Schroeder, a Class B dealer, had his license revoked when he was accused of having “willfully violated the Animal Welfare Act” by obtaining seven dogs illegally, failing to provide proper housing, and refusing to allow USDA inspectors access to his records and facilities. A HBO documentary Dealing Dogs reveals the horrifying conditions of C.C. Baird’s facility Marin Creek Kennels. His license has since been revoked and he has been fined.
Laboratory Animal Care and Use
The Animal Welfare Act (AWA) is the most significant law governing the care and use of laboratory animals in the United States. Passed in 1966, the AWA has since been amended eight times and covers all warm-blooded animals, except for mice, rats, and birds. The AWA’s regulations spell out requirements for veterinary care, adequate food and water, protection from temperature extremes, shelter from outdoor elements, sanitation, and record keeping.
A separate piece of legislation, called the Health Research Extension Act, passed in 1985, covers all vertebrates — including mice, rats, and birds — used in research, testing, and education that is funded by the Public Health Service (PHS). The PHS Guide for the Care and Use of Laboratory Animals sets the standards for care and housing that must be provided to animals in PHS-funded studies.
Almost all animals in laboratories suffer to one degree or another from the stress of confinement, but they do not all experience pain or even distress as a result of experimental procedures. In 2019, the USDA reported that 66% of warm-blooded animals in laboratories covered by the AWA experienced no pain or distress or were not used in experiments, 28% experienced moderate to severe pain or distress that was relieved by anesthesia or analgesia (pain-killing medication), and the remaining 6% experienced unrelieved pain or distress. The USDA reported that 89,910 animals were held and used in research facilities in Massachusetts in 2019. Of those, 74% were reported to have no pain and no drugs or were not used in experiments, 22% had pain and drugs, and 4% had pain without drugs. Of course, these figures do not include rats, mice, and birds, which are not covered by the AWA. While some laboratory animals die as a result of experimental procedures, most are euthanized for postmortem examination or when they are no longer needed.
According to the AWA, facilities using animals for research, testing, or education must form an Institutional Animal Care and Use Committee (IACUC) to oversee their animal programs. IACUCs are composed of scientists, veterinarians, and at least one member of the general public who is not affiliated with the institution in any way. IACUCs not only inspect the institution’s laboratories, they must also review and approve all research protocols before any animals can be used. They also look for evidence that the investigator has made a concerted effort to find alternatives to research that might cause pain and distress, and if animals must be used, that there is a plan for alleviating that pain and distress. The amount of time and effort put into these efforts, however, varies widely. There are over 1,000 IACUCs associated with research, testing, and education laboratories across the United States today. A report by the Office of the Inspector General in 2014 (see link below) showed that in FY 2009-2011, 531 of 1,117 research facilities were cited with 1,379 IACUC-related violations regarding lack of oversight. Unfortunately, the USDA has only 57 veterinary medical officers and 68 inspectors (as of FY 2010) responsible for enforcing the Animal Welfare Act in over 8,656 facilities.
Alternatives to Animals in Research
While laboratory animals are the primary vehicle for research in the United States, an increasing number of alternatives to animal research now offer new hope for the welfare of millions of these animals used in biomedical research, product safety testing, and education. While the use of alternatives doesn’t always mean eliminating animals altogether, the number of animals being used has been dramatically reduced in recent years, and the lives of many others have been significantly improved. The words now used almost universally by the research community and by animal protection advocates to describe alternatives are the Three Rs – Replacement, Reduction, and Refinement.
The widely-applied concept of the Three Rs was originally introduced in the 1950s by William Russell and Rex Burch, British biologists who sought to lessen the suffering of laboratory animals. Replacement means substituting other systems for whole animal use. Reduction means decreasing the number of animals to the minimum needed to yield accurate data. Refinement means using modern medicine to minimize or eliminate pain and distress and employing housing and husbandry techniques to enrich the captive environment to reduce boredom and promote natural behavior. Please see our webpage on Laboratory Animal Alternatives – The Three Rs for more information.
What Can You Do?
Know that you are not alone. While the sheer scope of the issues impacting laboratory animals may seem daunting, individuals can make a positive impact on the welfare of laboratory animals in several ways:
- Be in the know. Public pressure has been the primary force behind all the improvements that have been made over the years in the laws and regulations protecting animals in laboratories. Join groups that promote laboratory animal welfare, such as the MSPCA, the New England Anti-Vivisection Society, the Physicians Committee for Responsible Medicine, and the American Anti-Vivisection Society. These organizations send e-newsletters and alerts to educate members about lab animal issues and let them know when their voice can help laboratory and other animals.
- Be an educated and conscientious consumer. Consider purchasing products made by companies that are doing the most to develop and promote alternatives to animals in testing their products’ safety. When making investments, consider those companies that don’t test on animals, don’t support animal-based research, or have committed to minimizing the number of animals used to test their products.
- Please see our information on Cruelty-Free Labeling and Product Safety Testing on our website.
- Be an educated learner. If you or members of your family are an educator or student of any level, educate yourself, your family, and your institution about alternatives to the harmful or invasive use of animals in the classroom.