Animal testing, or animal research, refers to the use of non-human animals in experiments. It is estimated that 50–100 million animals worldwide [4][5][6] are used annually and subsequently killed in scientific procedures — conducted as part of pure research, applied research, or toxicology testing — mostly inside universities, medical schools, pharmaceutical companies, and commercial facilities that provide animal-testing services to industry. Testing is also carried out on farms, in defense-research establishments, and by public-health authorities, on a variety of species from fruit flies and mice to non-human primates. [7] Most laboratory animals are purpose bred, while a smaller number are caught in the wild or supplied by pounds. [8]
The topic is controversial, with supporters and opponents arguing about ethical issues and the scientific necessity of using animal models. The Foundation for Biomedical Research, an American organization that "promot[es] public understanding and support for humane and responsible animal research," writes that "[a]nimal research has played a vital role in virtually every major medical advance of the last century — for both human and animal health," and that many major developments that led to Nobel Prizes involved animal research, including the development of penicillin (mice), organ transplant (dogs), and work on poliomyelitis that led to a vaccine (mice, monkeys). Whether animal research was necessary to achieve these results has been questioned by animal rights groups and other critics of the animal model.
One moral basis for a pro-testing position was summarized by a British House of Lords report in 2002: "the whole institution of morality, society and law is founded on the belief that human beings are unique amongst animals. Humans are therefore morally entitled to use animals, whether in the laboratory, the farmyard or the house, for their own purposes." This belief is "combined with a further belief that there is a moral imperative ... to develop medical and veterinary science for the relief of suffering ..." and "we have a moral duty to avoid or minimise animal suffering wherever possible" Some people also believe that animals may suffer less during experiments than human beings would, arguing that although all mammals have similar pain receptors and central nervous system pathways and may feel physical pain in the same way, non-human mammals suffer less because they have a reduced capacity to remember and to anticipate pain. Opponents of animal testing strongly contest these views.
The earliest references to animal testing are found in the writings of the Greeks in the third and fourth centuries BCE, with Aristotle (384-322 BCE) and Erasistratus (304-258 BCE) among the first to perform experiments on living animals (Cohen and Loew 1984). Galen, a physician in second-century Rome, dissected pigs and goats, and is known as the "father of vivisection." [17]
Animals have had a role in numerous well-known experiments. In the 1880s, Louis Pasteur convincingly demonstrated the germ theory of medicine by giving anthrax to sheep. In the 1890s, Ivan Pavlov famously used dogs to describe classical conditioning. Insulin was isolated first from dogs in 1922, and revolutionized the treatment of diabetes. On November 3, 1957 a Russian dog named Laika became the first of many animals to orbit the earth. In the 1970s, leprosy multi-drug antibiotic treatments were developed first in armadillos, then in humans. In 1996 Dolly the sheep was born, the first mammal to be cloned from an adult cell.
Listed in descending order of numbers of individual animals used:
Invertebrates
Most of the animals used in animal testing are invertebrates, especially Drosophila melanogaster, a fruit fly, and Caenorhabditis elegans, a nematode. In the case of C. elegans, the precise lineage of all of the organism's cells is known, and D. melanogaster has various characteristics making it well suited to genetic studies. These animals offer scientists a number of advantages over vertebrates, including their short life cycle and the ease with which large numbers of individuals may be studied. Invertebrates are often extremely cost-effective, as thousands of flies or nematodes can be housed in a single room, but this is not true for all species of invertebrates.
With the exception of some cephalopods, invertebrate species are not protected under most animal research legislation, and therefore the total number of invertebrates used remains unknown.
Rodents
Rodents commonly used include guinea pigs, hamsters, gerbils, rats and mice. Mice are the most commonly utilized vertebrate species, popular because of their availability, size, low cost, ease of handling, and fast reproduction rate. Mice are widely considered to be the prime model of inherited human disease and share 99% of their genes with humans. [49] With the advent of genetic engineering technology, genetically modified mice can be generated to order. The Mouse Genetics Core at Washington University in St. Louis [50] explains what is required to produce today's widely used transgenic and chimeric mice:
Production of Transgenic Mice The Transgenic Animal Production service consists of injecting each construct into 300-350 eggs, typically representing three days work. Twenty to fifty mice will normally be born from this number of injected eggs. These animals are screened for the presence of the transgene by a polymerase chain reaction genotyping assay. The number of transgenic animals typically varies from two to eight.
Production of Chimeric Mice The chimeric mouse production service consists of injecting embryonic stem cells provided by the investigator into 150-175 blastocysts, representing three days of work. Thirty to fifty live mice are normally born from this number of injected blastocysts. Normally, the skin color of the mice from which the host blastocysts are derived is different from that of the strain used to produce the embryonic stem cells. Typically two to six mice will have skin and hair with greater than seventy percent ES cell contribution, indicating a good chance for embryonic stem cell contribution to the germline.
In the UK in 2004, 1,910,110 mice, 464,727 rats and 37,475 other rodents were used (84.5% of the total animals used that year). In 2005 the total number of rodents used was similar to the previous year: 1,955,035 mice, 414,335 rats and 40,856 other rodents. [47]
In the U.S., the numbers of rats and mice used are not reported, but have been estimated at 15-20 million. [51] In 2000, the Federal Research Division, Library of Congress, published the results of an analysis of its Rats/Mice/and Birds Database: Researchers, Breeders, Transporters, and Exhibitors. [52]
Over 2,000 research organizations are listed in the database, of which approximately 500 were researched and of these, 100 were contacted directly by FRD staff. These organizations include hospitals, government organizations, private companies (pharmaceutical companies, etc.), universities/colleges, a few secondary schools, and research institutes. Of these 2,000, approximately 960 are regulated by USDA; 349 by NIH; and 560 accredited by AALAC. Approximately 50 percent of the organizations contacted revealed a specific or approximated number of animals in their laboratories. The total number of animals for those organizations is: 250,000-1,000,000 rats; 400,000-2,000,000 mice; and 130,000-900,000 birds.
Fish and amphibia
In the UK, 194,562 fish and 18,195 amphibia were used in 2004 [53] PDF. In 2005, the number of fish used increased to 230,315 while the number of amphibia used decreased to 13,318. [47] The major species utilized are the zebrafish, Danio rerio, which are translucent during their embryonic stage, and the African clawed frog, Xenopus laevis.
Rabbits
Over 20,000 rabbits were used for animal testing in the UK in 2004. This number decreased, in 2005, to 15,348. [47] Albino rabbits are used in eye irritancy tests because rabbits have less tear flow than other animals and the lack of eye pigment make the effects easier to visualize. They are also used in skin irritancy tests (see Draize test). In 2004 less than 12% of the rabbits were used for safety testing of non-medical products [54].
Dogs
Beagles are used, because they are friendly and gentle, in toxicity tests, surgery, and dental experiments. Toxicology tests are required to last six months in the UK, although British laboratories carry out tests lasting nine months on behalf of Japanese and American customers. Of the 8,018 dogs used in the UK in 2004, 7,799 were beagles (97.3%). PDF In 2005 the number of dogs used in the UK decreased to 5,373. Most dogs are bred specifically for the purpose, for example by Harlan in Leicestershire.
Non-human primates
In the United States, 54,998 non-human primates (NHPs) were used in 2004, according to the U.S. Department of Agriculture (USDA), an annual figure that has been more or less steady since 1973 . In the European Union, 10,000 are used each year, with 4,208 used in Britain in 2004, a decrease of 591 from the previous year. This decreasing trend continued in 2005, with 3,115 primates used in the UK.
Primates are the species most likely to be re-used in experiments. Re-use is allowed if the animals have been used in mild procedures with no lasting side-effects, according to the Research Defence Society. [51] BUAV report that it is because of re-use that there has been a fall in the number of individual primates used in the UK.
Most of the NHPs used are baboons, macaques, marmosets, and chimpanzees. Licenses approving the use of non-human primates, such as gorillas, chimpanzees, and orangutans (also known as Hominidae), are not currently being issued in Britain, though their use has not been outlawed, but chimpanzees are used in the U.S., with an estimated 1,300 still remaining in research laboratories, according to The Humane Society of the United States. NHPs are used in research into HIV, neurology, behavior, cognition, reproduction, Parkinson's disease, stroke, malaria, respiratory viruses, infectious disease, genetics, xenotransplantation, drug abuse, and also in vaccine and drug testing. According to The Humane Society of the United States, chimpanzees are most often used in hepatitis research, and monkeys in HIV research, and are often housed alone because of the nature of the conditions being studied.
There are indications that NHP use is on the rise, in part because biomedical research funds in the USA have more than doubled since the 1990s. In the U.S., the Oregon and California National Primate Research Centers and New Iberia Research Center have expanded their facilities[56][57][58]; in 2000 the National Institutes of Health (NIH) invited applications for the establishment of new breeding specific pathogen free colonies[59]; and a new breeding colony projected to house 3,000 NHPs has been set up in Florida[60]. The NIH's National Center for Research Resources identified a need to increase the number of breeding colonies in its 2004-2008 strategic plan, as well as to set up a database, using information provided through a network of National Primate Research Centers, to allow researchers to locate NHPs with particular characteristics. China is also increasing its NHP use, and is regarded as attractive to Western companies because of the low cost of research, the relatively lax regulations and the increase in animal-rights activism in the West.
In 2004, the British government reported "a definite long-term downward trend" in the use of new world primates (for example, marmosets, tamarins, squirrel, owl, spider and capuchin monkeys), but stated that the use of old world primates (for example, baboons and macaques) fluctuates and is more difficult to determine. Crab-eating macaques and rhesus macaques are the most commonly used species. [52] Home Office figures show the number of primates used in the UK rose by 11 per cent in 2005 to 4,650 procedures, 440 more than in 2004.
Most primate use in the UK is in applied studies, which the Home Office defines as research conducted for the purpose of developing or testing commercial products. Toxicology testing is the largest use. The second largest category of research using primates is "fundamental biological research." This includes inducing brain damage in order to research Parkinson's, studying visual and auditory functions, and cognitive research.
In 1996, the British Animal Procedures Committee recommended new measures for dealing with NHPs. The use of wild-caught primates was banned, except where "exceptional and specific justification can be established"; specific justification must be made for the use of old world primates (but not for the use of new world primates); approval for the acquisition of primates from overseas is conditional upon their breeding or supply center being acceptable to the Home Office; and each batch of primates acquired from overseas must be separately authorized.
CATS
Felines are most commonly used in neurological research. In the UK in 2005, 308 cats were used. This is a decrease from 819 cats recorded in 2004 . According to the USDA, over 25,500 felines were used in the USA in 2000, of these around half were reported to have been used in experiments that caused "pain and/or distress". The number of cats used in research in the US has followed a downward trend, from a peak of 74,259 in 1973.
Types of experiment=Experiments can be split into three broad, overlapping categories: pure research, in which experiments are conducted that have no direct commercial application, with a view to advancing knowledge, most often inside universities; applied research, conducted in order to solve specific biological problems or to develop commercial products, either for medical or non-medical use; and toxicology or safety testing, in which commercial products are tested on animals to measure potential adverse biological reactions to the ingredients.
Pure research
Basic or pure research aims to increase knowledge about the way organisms behave, develop, and function biologically.
Both the largest number and greatest variety of laboratory animals are used in this type of research. Drosophila melanogaster, Caenorhabditis elegans, mice and rats together account for the vast majority, though small numbers of other species are used, ranging from sea slugs through blind cavefish [60]. In the UK in 2005, 89 macaques, 114 marmosets, 133 dogs and 237 cats were used in basic research to investigate topics such as social behaviour, vision, nutrition and suckling. [47]
Examples of the types of animals and experiments used in basic research include:
Mutagenesis to study mechanisms in embryogenesis and developmental biology. Animals are often treated with mutagenic chemicals or radiation to generate defective embryos. By studying disrupted development, scientists aim to understand both how organisms develop normally and abnormally [61]. The 1995 and 2002 Nobel Prizes in Physiology or Medicine were awarded for research into developmental processes in animals using forward genetic screens [62][63]. Embryos used in experiments are often not covered by legislation and therefore not always required to be reported. Consequently, those that believe embryos are de facto animals claim the published number of experimental animals used is an under-representation.
Experiments into behaviour, to understand how organisms detect and interact with each other and their environment. Fruit flies, worms, mice and rats are all widely used in research into mechanisms of vision, [64] taste, [65] hearing, [66] touch, [67] and smell. [68] In addition studies of brain function, such as memory and social behaviour, often use rats and birds. [69] Less common is the use of larger mammals in these types of studies.
Breeding experiments to study evolution and genetics. Laboratory mice, flies, fish and worms are inbred through many generations to create strains with defined characteristics [70] [71]. These provide scientists with animals of a known genetic background, an important tool for genetic analysis that is currently not available when studying outbred subjects (such as most human populations). Larger mammals are rarely bred specifically for such studies due to their longer gestation periods, though some scientists take advantage of inbred domesticated animals, such as dog or cattle breeds, for comparative purposes [72]. Scientists studying mechanisms of evolution use a number of animal species, including mosquitos [73], sticklebacks [74], cichlids [75] and lampreys [76], due to their niche physiology, morphology, ecology or phylogeny.
Applied research
Applied research aims to solve specific and practical problems, often relating to the treatment or cure of disease and disorder in humans and other animals.
Compared to pure research, which is largely academic in origin, applied research programmes are more likely to be carried out in the pharmaceutical industry, or in universities in commercial partnership. These may involve the use of animal models of disease or condition, which are often discovered or generated by pure research programmes. In turn, such applied studies may be an early stage in the modern drug discovery process. Examples of animal use in this type of research include:
Genetic modification of animals to study disease. Transgenic animals have specific genes inserted, modified or removed, with the aim of modelling a specific condition. The aim of these models may be to exactly mimic a known single gene disorder, such as Duchenne muscular dystrophy or albinism, then use the model to investigate novel ways it may be treated. Other models are generated to approximate complex, multifactorial disease with a genetic component, such as cancer or Alzheimer's disease, then investigate how and why the disease develops. The vast majority of transgenic models of disease are mice [77], the mammalian species in which genetic modification is most efficient, though there are smaller numbers of other animals such as rats, sheep and pigs [78]. Pharmaceutical companies [79], medical research institutes [80], politicians [81], scientists [82] and professional research bodies widely endorse these techniques, describing an "explosion of research on such disease models" [83] resulting in "an increasingly important role in the discovery and development of new medicines" [84]. However, animal rights and welfare groups regularly question the value and effectiveness of transgenic techniques, [85] [86] as animals do not always model human diseases accurately [87] or in their entirety. [88] [89] Public interest group, GeneWatch UK, reports that genetic modification is "highly inefficient, wasteful of animal lives" and calls for "balancing the needs of people for drugs with the welfare and integrity of animal species." [90]
Studies on models of naturally occurring disease and condition. Certain domestic and wild animals have a natural propensity or predisposition for certain conditions that are also found in humans. Cats, for example are used as a model to develop immunodeficiency virus vaccines due to their natural predisposition to FIV infection [91]. Their infection with a related feline virus, FeLV, makes cats a common model for leukemia research also. [92] Certain breeds of dog suffer from narcolepsy [93] [94] (video) making them the major model used to study the human condition. Armadillos and humans are among only a few animal species that naturally suffer from leprosy [95]. As it cannot yet be grown in culture, armadillos are the primary source of bacilli used in leprosy vaccines. [96] Non human primates, being closely related to humans, are applied in the study of a number of human conditions, including visual disorders [97] [98] and dental disease [99]. Primates are also used extensively in immunology [100] and reproductive studies [101] [102], a synthesis of which resulted in the discovery of the Rhesus factor and its importance in hemolytic disease of the newborn.
Xenotransplantation research, primarily using primates as the recipient of pig hearts. The British Home Office released figures in 1999 showing that 270 monkeys had been used in xeno research in the UK during the previous four years. In 1999, three baboons and 79 cynomolgus monkeys were used.
According to licensing agencies, the increased experimentation on xenotransplation is motivated by the desire to save human lives. The US FDA says "The development of xenotransplantation is, in part, driven by the fact that the demand for human organs for clinical transplantation far exceeds the supply. Currently ten patients die each day in the United States while on the waiting list to receive life-saving vital organ transplants. Moreover, recent evidence has suggested that transplantation of cells and tissues may be therapeutic for certain diseases such as neurodegenerative disorders and diabetes, where, again human materials are not usually available."[67]. In Great Britain, the government agency UKXIRA states "There is currently, and will continue to be, a shortage of human organs and tissue for transplantation....Xenotransplantation is a potential solution to this shortage. "[68] Author G. Wayne Miller, in The Xeno Chronicles, suggests another motivation:
Assuming xeno could be perfected, the group that brought xeno to the clinic first would claim not only scientific accolades but also a good share of the market that a Saloman Brothers study had predicted would reach $6 billion by 2010. The estimate did not seem unreasonable. No one could state what a working pig organ would cost, but with so many desperate patients and with waiting lists for all organs growing, the seller could all but command his price.[69]
Medical journalists Jenny Bryan and John Clare have called xenotransplatation experiments "some of the most grisly procedures carried out anywhere in the name of science." They write that: "They do sometimes involve a full transplant of a genetically modified pig heart into a monkey. In some cases, however, the doctors will graft the transgenic hearts onto a baboon's neck arteries, as this allows them to observe the way the pig heart behaves in another species, and monitor the rejection process. The operation is carried out under general anaesthetic and the baboon is humanely killed afterwards. These measures, however, do not pacify animal rights campaigners, who say the experiments are cruel and unnecessary." [70] Details of the effects of these experimental procedures came to light when thousands of documents were leaked to a UK-based animal rights organization. After a legal battle, the documents were published in a report titled Diaries of Despair.
Drug testing=In response to the teratogenic effects of Thalidomide in the 1960s, many countries passed new laws to ensure all new pharmaceuticals underwent rigorous animal testing before being licensed for human use. Tests on pharmaceutical products involve:
metabolic tests, which are performed to find out how the drugs are absorbed, metabolized and excreted by the body when introduced orally, intravenously, intraperitoneally, or intramuscularly.
toxicology tests, which gauge acute, sub-acute, and chronic toxicity. Acute toxicity is studied by using a rising dose until signs of toxicity become apparent. Current European legislation, Directive 2001/83/EC [104] (pdf, p44), demands "acute toxicity tests must be carried out in two or more mammalian species" covering "at least two different routes of administration". Subacute toxicity is where the drug is given to the animals for four to six weeks in doses below the level at which it becomes toxic, in order to discover the effects of the build up of toxic metabolites. Testing for chronic toxicity can last up to two years and, in the European Union, is required to utilize "two species of mammals, one of which must be non-rodent" [105] (pdf, p45). The data gained from this period can be used to calculate the maximum tolerable dose; that is, the dose where signs of toxicity begin to occur.
efficacy studies, which test whether experimental drugs work by inducing the appropriate illness in animals using an animal model of the disease. The drug is then administered in a double-blind controlled trial. This is intended to allow scientists to determine the effect of the drug and the dose-response curve.
Specific tests on reproductive function, embryonic toxicity or carcinogenic potential can all be required by law, dependent of the result of other studies and type of drug being tested.
Cosmetics testing=Cosmetics testing is particularly controversial. It is banned in the Netherlands, Belgium, and the UK, and in 2002, after 13 years of discussion, the European Union (EU) agreed to phase in a near-total ban on the sale of animal-tested cosmetics throughout the EU from 2009, and to ban all cosmetics-related animal testing. [106] France, which is home to the world's largest cosmetics company, L'Oreal, has protested the proposed ban by lodging a case at the European Court of Justice in Luxembourg, asking that the ban be quashed. The ban is also opposed by the European Federation for Cosmetics Ingredients, which represents 70 companies in Switzerland, Belgium, France, Germany and Italy. [107]
Cosmetic testing on animals includes:
testing a finished product such as lipstick;
testing individual ingredients, or a combination of them;
Contracting a third-party company to perform any of the above;
Using a subsidiary or third-party company to perform the tests in countries where animal testing is not banned.
Some cosmetics companies continue to make the claim that their products are not tested on animals despite using one or more of the above practices.
Re-using existing test data obtained from previous animal testing is generally not considered to be cosmetic testing on animals; however, the acceptability of this to opponents of testing is inversely proportional to how recent the data is.
Due to the strong public backlash against cosmetic testing on animals, most cosmetic manufacturers say their products are not tested on animals. However, they are still required by trading standards and consumer protection laws in most countries to show their products are not toxic and dangerous to public health, and that the ingredients are not dangerous in large quantities, such as when in transport or in the manufacturing plant. In some countries, it is possible to meet these requirements without any further tests on animals. In other countries, it may require animal testing to meet legal requirements. The United States and Japan are frequently criticised for their insistence on stringent safety measures, which often requires animal testing, although the U.S. has also been a leader in developing cell culture alternatives.
Some retailers distinguish themselves in the marketplace by their stance on animal testing. The British Co-op maintains a cosmetic-testing website, [108] which includes statements from all their suppliers about the extent of their animal testing. The Body Shop is also well-known for its campaigns against animal testing. [109]
Although the British Home Office stopped giving licences to test finished cosmetic products in 1998, compounds that have both cosmetic and medical uses, such as those in the "anti-wrinkle" preparations Zyderm, Restylane and Botox, are still bound by the regulations requiring animal testing. According to activists, a raid on a laboratory in 2004 revealed that the LD50 test is still used on every batch of Botox (a toxin that, when administered intravenously, is lethal to humans) to establish potency [110] [111] [112].
While some cosmetics manufacturers have genuinely stopped all animal testing of their products, others continue to test. Companies that continue to perform cosmetic testing on animals may falsely claim that they do not do this in their advertising and on their products — or choose not to state either way.
Cosmetics manufacturers who genuinely do not test on animals generally use the following for safety testing of their products:
reliance on existing natural or synthetic ingredients, compounds and substances, which have already been extensively tested on animals;
avoiding novel ingredients or combinations of ingredients that have not been fully tested and may not be safe;
testing on human volunteers/clinical trials.
This presumes that cosmetics companies are already using computer modeling and cell cultures to simulate human tissue, two techniques that have had ambiguous utility in discovering problems early. Supporters of animal testing say that neither can fully replace live human or non-human animal tests.
Both proponents and critics of animal experimentation have claimed that the majority of the general public support their position according to opinion polls.
The Foundation for Biomedical Research used a HART poll [83] in 2005 which asked American subjects to choose a statement they agree with more. The first statement was "Animal research is inhumane and unnecessary. Many lab animals endure painful experiments in cramped/dirty conditions. Animal research can be replaced with modern alternatives such as computer simulations and it can be dangerous, as results in animals are not comparable to those in humans." The second statement was "U.S. places strict regulations on treatment of research animals, scientific community is working hard to develop alternatives to animal research and already uses some alternatives. However, the most reliable tests use animals because they most closely duplicate complex interactions that occur in humans." 56% agreed with the second statement more, compared to 27% who agreed more with the first.
In Great Britain, more than 70% of those surveyed in a Telegraph/YouGov poll "accepted that experimentation on animals was sometimes essential because alternative methods were unavailable."[84] This poll was published in June 2006. The increased public favoritism relative to older polls was attributed to public concern that animal testing would simply move out of Great Britain, and that more than three quarters of the public believes "the more fanatical activists can justifiably be defined as 'terrorists'". Older polls came closer to a 50/50 split on similar issues.
One such older poll was conducted in Great Britain by ICM, which was commissioned by the Research Defence Society, an organisation that advocates animal experimentation [85]. When asked, "Do you agree or disagree with the use of animals in experiments to test new medicines?" 50% Agreed, 47% disagreed, 3% did not know.
A more recent ICM poll was commissioned by BBC Newsnight and published in July 2006. [86] Asked "Do you believe it is acceptable or not acceptable to use animals for medical research?" 57% responded that it was completely, or quite acceptable, whereas 40% responded it was either not very acceptable or not at all acceptable.
A MORI poll [87] tracked public sentiment on animal testing in the UK from 1999 to 2002. They found the number of people who were "conditional acceptors" of animal testing rose from 84% to 90% over that time. A conditional acceptor agrees with testing meeting the four conditions of the experiment being for medical research purposes, into life threatening diseases, with no un-necessary suffering, and non-animal alternatives being used whenever possible.
However, these opinions are strongly subject to the wording used in polls. A BUAV poll carried out by TNS in 2003 found 76% of respondents thought the British Government “should, as a matter of principle, prohibit experiments on any live animals which cause pain, suffering, distress or lasting harm”.[88] A 2001 US poll conducted on behalf of the Humane Society of the United States found that 75% of the people polled disapprove of experiments that subject animals to severe pain and distress, 33% indicated they disapprove of animal experimentation that involves little or no pain or distress, and 62% approve of experiments that involve little or no pain or distress. [89]
Alternatives to animal testing
Most scientists and governments say they agree that animal testing should cause as little suffering to animals as possible, and that animal tests should only be performed where necessary. The "three Rs" [126] are guiding principles for the use of animals in research in many countries:
Reduction refers to methods that enable researchers to obtain comparable levels of information from fewer animals, or to obtain more information from the same number of animals.
Replacement refers to the preferred use of non-animal methods over animal methods whenever it is possible to achieve the same scientific aim.
Refinement refers to methods that alleviate or minimize potential pain, suffering or distress, and enhance animal welfare for the animals still used.
Groups opposed to animal testing are divided in their position on the 'three Rs'; some support the principles [127] while others accept replacement as the only valid action [128]. There are a number of scientific studies [129] and institutes [130] researching alternatives to animal tests. However, critics say these facilities perpetuate the myth that animal experiments are necessary for human health, and are only there to reassure the public that steps are being taken to find alternatives [131][132]. It is further stated these studies are funded with trivial amounts of money [133][134], but this view is contested by the UK pharmaceutical industry, which estimates more than £300 million (of a total UK R&D budget of £3285 million) is spent on 'three R' development and implementation annually [135] (pdf).
The two major, widely accepted alternatives to animal testing under development are computer simulations and in vitro cell culture techniques. However, some claim they are not true alternatives since simulations use data from prior animal experiments and cultured cells often require animal derived products, such as serum. Others say that they cannot replace animals completely as they are unlikely to ever provide enough information about the complex interactions of living systems [136]. Examples of computer simulations available include models of diabetes [137], asthma [138], and drug absorption, though potential new medicines identified using these techniques are currently still required to be verified in animal tests before licensing.
Cell culture is currently the most successful, and promising, alternative to animal use. For example, cultured cells have also been developed to create monoclonal antibodies, prior to this production required animals to undergo a procedure likely to cause pain and distress [139].
A third alternative now attracting considerable interest is so-called microdosing, in which the basic behaviour of drugs is assessed using human volunteers receiving doses well below those expected to produce whole-body effects [140] (pdf).
Institutes researching (and organizations funding) alternatives to animal testing include:
The Johns Hopkins Center for Alternatives to Animal Testing
The University of California Center for Animal Alternatives
Dr Hadwen Trust
The Fund for the Replacement of Animals in Medical Experiments [141]
The National Centre for Replacement, Refinement and Reduction of Animals in Research [142]
The 3R Research Foundation .
Advocates of animal testing
Testing advocates argue that:
It would be unethical to test substances or drugs with potentially adverse side-effects on human beings. [144]
Controlled experiments involve introducing only one variable at a time, which is why animals are experimented on while confined inside a laboratory. Human beings could not be confined in this way. [145]
There is no substitute for the living systems necessary to study interaction among cells, tissue, and organs. Animals are good surrogates because of their similarities to humans. [146]
There is no substitute for psychiatric studies (e.g., antidepressant clinical trials) that require behavioral data.
There is no substitute for studies of the infection of a host by lethal pathogens, for example ebola or HIV.
Animals have shorter life and reproductive spans, meaning that several generations can be studied in a relatively short time.
Animals can be bred especially for animal-testing purposes, meaning they arrive at the laboratory free from disease.
Humans that use medicine derived from animal research are healthier. [147]
Animals receive more sophisticated medical care because of animal tests that have led to advances in veterinary medicine. [148]
There have been several examples of substances causing death or injury to human beings because of inadequate animal testing. [149]
Activists manipulate and fabricate facts, therefore their claims are not reliable.
Alternatives to certain kinds of animal testing are unknown.
Wherever practical alternatives exist, they are often likely to be introduced for economical reasons, like testing on rodents instead of primates because of their lower cost of keeping.
Over 10 times more animals are used by humans for other purposes (pets, agriculture, hunting, pest control) than are used in animal testing, with roughly 130 million pet dogs and cats in the USA, 100 million animals killed by hunting, 150 million large mammals used in agriculture, and hundreds of millions of rats involved in pest control.
Opponents of animal testing
Opponents argue that:
Even with medical and non-commercial research, tests are often conducted to produce academic papers in order to acquire a Ph.D., academic tenure, or more funding, and not because the research is beneficial.
The suffering of the animals is excessive in relation to whatever benefits may be reaped. [150] (pdf)
Animal-testing facilities are not properly regulated or inspected, and several undercover investigations by activist groups have uncovered evidence of animal abuse.
Animal testing is regarded by opponents as bad science because they believe:
Some animal models of disease are induced, and should not be compared to the same disease in humans. Activists claim Parkinson's disease in humans cannot be reproduced by causing brain damage in an animal [151], though genetic and toxin-mediated animal models are now widely used [152].
Some drugs have dangerous side-effects that were not predicted by animal models. Opponents often claim Thalidomide as an example of this is [153], although when tested on pregnant animals, birth defects are seen in mice, rats, hamsters, rabbits, macaques, marmosets, dogs, cats, fish, baboons and rhesus monkeys [154].
Some drugs appear to have different effects on human and non-human animals. Aspirin, for example, is a teratogen when given to certain animals in high doses [155], but there is conflicting evidence regarding its effect on human embryos [156] [157].
The conditions in which the tests are carried out may undermine the results, because of the stress the environment produces in the animals. BUAV argues that the laboratory environment and the experiments themselves are capable of affecting every organ and biochemical function in the body. "Noise, restraint, isolation, pain, psychological distress, overcrowding, regrouping, separation from mothers, sleeplessness, hypersexuality, surgery and anaesthesia can all increase mortality, contact sensitivity, tumour susceptibility and metastatic spread, as well as decrease viral resistance and immune response." [158]
The most vocal proponents of animal testing are the vested interests.
Some opponents, particularly supporters of animal rights, argue further that, even if animal testing did reap benefits to human beings, these could not outweigh the suffering of the animals, and that human beings have no moral right to use individual animals in ways that do not benefit that individual.
2006-10-19 21:25:55
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answer #4
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answered by shiva 3
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