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Animal testing

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Filmed by PETA, Covance primate-testing lab, Vienna, Virginia, 2004-5. [1]

Animal testing refers to the use of non-human animals in experiments. Worldwide, around 100 million animals are used in experiments before being killed every year. [2] (pdf)

Most animal testing takes place in laboratories set up for that purpose, either in universities or in commercial facilities that provide animal-testing services to industry, such as Huntingdon Life Sciences in the United Kingdom and United States. Testing is also carried out on farms and in defense-research establishments. Animals used in tests include mice, rats, fish, birds, guinea pigs, hooved mammals, rabbits, dogs, non-human primates, and cats. [3]

Animal experiments fall into three broad and overlapping categories. Animals are used in pure research, conducted without practical application for the "advancement of knowledge," [4] an example of which would be psychological testing; applied research, directed toward a specific application such as the treatment of human and non-human disease; and toxicology testing, which is the testing of specific ingredients or products on behalf of the manufacturers of pharmaceuticals, industrial and agricultural chemicals, cosmetics, and household products such as washing-up liquid. Most toxicology testing is required by law.

The topic is mired in controversy, with supporters and opponents arguing over both ethical concerns, and the issue of whether using animal models is good or bad science. Animals are used in tests in part because of the belief that human beings are morally entitled to use animals in procedures that would be unacceptable if conducted on other human beings [5]; and in part because many people also believe that animals suffer less during experiments than human beings would. Their argument is that, although human and non-human mammals have similar pain receptors and central nervous system pathways, and may feel physical pain in the same way, non-human animals suffer less because they have a reduced capacity to remember and to anticipate pain, and a reduced understanding of the implications of their confinement. [6] Opponents of animal testing strongly contest these views.

Terminology

The term "vivisection" means the "cutting up" of a living animal. Although originally it referred only to experiments that involved dissection of, or surgery on, live animals, it is now used to refer to any experiment on a living animal, also called in vivo testing (Croce 2000). [7]

Numbers of animals used

File:LD50mouse.jpg
A rat undergoing an LD50 test

Accurate global figures for animal testing are hard to obtain. The British Union for the Abolition of Vivisection (BUAV) estimates that 100 million animals are experimented on around the world every year, 10–11 million of them in the European Union. Animals bred for research then killed as surplus are not included in the figures. [8] (pdf)

In the UK, detailed figures are made available by the British Home Office. These show that, in 2003, 2,791,781 procedures were carried out on 2,721,599 animals. The term "procedure" refers to an experiment, which might last several months or even years. The figures show that most animals are used in only one procedure: animals either die because of the experiment or are killed and dissected afterwards.

Over half the experiments in Britain in 2003 — 1,691,897 — were conducted without anesthetic; 832,926 experiments were conducted in connection with pure research; 435,943 were toxicology tests, and 16,596 involved the deliberate infliction of "psychological stress". Included among the species used were 1,809,795 mice; 11,398 pigs; 5,088 dogs, of which 4,984 were beagles (used because they are friendly and gentle); and 3,073 primates.

The types of institutions conducting the research were: universities (40.5 per cent); commercial organizations (36 per cent); non-profit organizations (4.9 per cent); government departments (2.6 per cent); National Health Service hospitals (0.9 per cent); public health laboratories (0.6 per cent); other public bodies (14.6 per cent). [9] (pdf)

Species used

Rats and mice are used in large proportion because they are small, cheap, easy to handle and care for, and can produce up to 100 babies in a year. Albino rabbits are used in eye irritancy tests because they have less tear flow than other animals. Beagles and primates are used in toxicity tests, surgery, dental experiments, and brain research. Most of the primates used are baboons, macaques, marmosets, and chimpanzees.

The most common use of dogs is in toxicology tests, which in Britain are required to last six months, although British laboratories carry out tests lasting nine months on behalf of Japanese and American customers. In the UK, most dogs are bred for the purpose, for example by Harlan in Leicestershire.

Types of experiment

Toxicology tests

File:Draizerabbit.jpg
A rabbit undergoing a Draize test

Toxicology tests are conducted by pharmaceutical companies testing drugs, or by animal-testing facilities like Huntingdon Life Sciences and Inveresk Research International on behalf of a wide variety of customers, including manufacturers such as Proctor and Gamble, Unilever, Reckitt Benckiser, Colgate-Palmolive, SC Johnson, Union Carbide, and Ciba-Geigy. Well-known household products tested on animals include Domestos, Parazone, Ajaz, Jif, Mr. Muscle, Flash, Mr. Sheen, Fairy washing-up liquid, Ariel, and Dettox. [10]

During these tests, which are conducted without pain relief in part to ensure no interference with the test results, finished products like pesticides, medications, food additives such as artificial sweeteners, cosmetics, and household products such as air freshener — or the chemical ingredients of any of these products — are applied to the skin, dripped into the eyes, injected, fed into the stomachs of the animals through a nasal-gastric tube, or introduced into their lungs by placing masks over their faces, or by placing the animals in an inhalation chamber. Doses may be given once, or repeated regularly for many months. Toxic effects include vomiting, dizziness, tremor, lethargy, loss of appetite, convulsions, paralysis, and death.

The LD50 test involves giving the substance to two species to find out what dose kills half the test population: this dose is referred to as the LD50, or Lethal Dose, 50%. The test has been banned in Britain and the oral LD50 (where animals are force fed a substance) was phased out of the Organisation for Economic Cooperation and Development's guidelines in December 2002. The inhaled and skin-application LD50 tests remain in the guidelines.

The Draize test involves dropping chemicals directly into the eyes of a conscious rabbit, which is usually held immobilized in stocks. The eyes are then observed for seven days for signs of swelling, discharge, ulceration, hemorrhaging, or blindness, after which the rabbit is killed.

Skin irritancy tests involve shaving the animals, usually rabbits and guinea pigs, and placing the test substance directly onto their skin.

Most toxicity tests involve testing ingredients rather than finished products. However, according to BUAV, manufacturers regard these tests as crude and believe they overestimate the toxic effects of the substances. They therefore repeat the tests using their finished products in order to obtain a less toxic label. [11] (pdf)

Other toxicity tests include the:

  • 90-day repeat-dose test, administered by mouth, inhalation, or skin to 30-80 rats, rabbits, or guinea pigs;
  • 90-day-repeat-dose test by mouth in non-rodents, in which dogs are used;
  • teratogenicity test, which tests for the effects of a substance on a foetus, and involves at least 80 mice, rats, hamsters, or rabbits;
  • chronic toxicity test, which involves at least 160 rats, who are given daily doses of the substance for most of their lifespan;
  • carcinogenicity test, another lifetime study testing for cancer in 400-500 rodents;
  • one- and two-generation reproduction toxicity test, which involves more than 100 rats or mice;
  • test for embryonic genetic damage, which involves 10-60 rats, hamsters, mice and their offspring;
  • toxicokinetic study involves eight to ten animals to study the absorption, metabolism, distribution, and extrection of a substance. [12] (pdf)

Toxicology tests involving drugs

Toxicology tests involving pharmaceutical products involve:

  • metabolic studies, which are performed to find out how the drugs are absorbed, metabolized and excreted by the body when introduced orally, intravenously, intraperitoneally, or intramuscularly.
  • safety studies, which gauge acute, sub-acute, and chronic toxicity. Acute toxicity is studied by using a rising dose until signs of toxicity become apparent. Sub-acute 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 as the build up of toxic metabolites. Testing for chronic toxicity can last up to two years in two different species. 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 works 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.

Controversy

Advocates of animal testing

Testing advocates argue that:

  • Humans in some parts of the world maintain a higher standard of living, in terms of their health, in large part due to advances in health and manufacturing knowledge derived from animal testing [13]
  • Animals receive more sophisticated medical care due to animal tests that have led to advances in veterinary medicine [14]
  • Animal models are the best option for exploring new medical treatments because: [15]
    1. Scientists can control for their genetic makeup
    2. Scientists can control for environmental conditions
    3. Animals breed quickly enough to provide a reasonable sample size

Opponents of animal testing

Opponents argue that:

  • The animal-testing industry is a multi-million dollar concern. Advocates of testing may argue that their interests are scientific, but they are just as often commercial.
  • Most animal testing is conducted for non-medical reasons. [citation needed]
  • 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 otherwise beneficial.
  • Animal testing is bad science and reaps either few benefits or none.
  • The suffering of the animals is excessive in relation to whatever benefits may be reaped.
  • Animal testing, especially for non-medical substances, is excessive and unnecessary.
  • Animal testing is regarded by opponents as bad science because:
    1. Animal models of disease are induced, and should not be compared to the same disease in humans. Parkinson's disease in humans cannot be reproduced by causing brain damage in an animal.
    2. Many drugs have dangerous side-effects that were not predicted by animal models; a well-known example of this is Thalidomide.
    3. Some drugs have different effects on human and non-human animals: aspirin, for example, is a teratogen in animals, but not in humans, and has beneficial effects on humans, such as stroke prevention, that are not reproduced in animals. [16]
    4. The conditions in which the tests are carried out may undermine the results, because of the stress the environment produces in the animals.
  • Animal liberationists further argue that, even if animal testing did reap benefits to human beings, these could not outweigh the suffering of the animals.

Abuse

File:It'sADog'sLife.gif
Clip from undercover footage filmed by PETA inside Huntingdon Life Sciences. The footage showed staff punching and screaming at beagles.

Undercover investigations by the British Union for the Abolition of Vivisection (BUAV) and People for the Ethical Treatment of Animals (PETA) have documented and filmed examples of animal abuse and apparent sadism in laboratories, which in most if not all countries are required, at least in theory, to adhere to animal-welfare regulations.

PETA filmed staff inside a British laboratory owned by Huntingdon Life Sciences (HLS), Europe's largest animal-testing facility, punching puppies in the face, screaming at them, and simulating sex acts while taking blood samples [17] (video). The film was subsequently shown as "It's a Dog's Life" on Channel 4 television in the UK in 1997, as a result of which Stop Huntingdon Animal Cruelty was formed, an international campaign to close HLS. In the United States, HLS technicians were filmed screaming and laughing at monkeys, and appearing to dissect one that was still alive [18] (video).

BUAV filmed staff in Covance, Europe's largest primate-testing center based in Germany, making monkeys dance in time to blaring pop music, handling them roughly, and screaming at them [19] (video).

In February 2005, while applying for a judicial review of laboratory practices in the United Kingdom, BUAV told the High Court in London that internal documents from the University of Cambridge's primate-testing labs showed that monkeys had had the tops of their heads sawn off to induce a stroke, and were then left alone after the procedure for 15 hours overnight, with their brains exposed and no veterinary care, because staff only worked from nine to five.

The BUAV judicial challenge followed a 10-month undercover investigation by BUAV into three research programmes at Cambridge in 1998. BUAV's lawyer, David Thomas, told the court: "Cambridge staff work 9-5pm, so animals who had just been brain damaged were left overnight without veterinary attention. Some were found to be dead in the morning, some were found to be in a worse condition. Yet there is an obligation of licence holders to keep suffering to a minimum. The whole system is very secretive and the public does not get to see what is really going on." [20]

Cosmetic testing on animals

File:NoAnimalTesting.gif
Products in Europe not tested on animals carry this symbol
File:BUAV-approved.gif
Products not tested on animals in the UK carry this British Union for the Abolition of Vivisection logo

Cosmetics testing is particularly controversial. It is banned in the Netherlands, Belgium, and the UK [21] (pdf), and in 2002, after 13 years of negotiations, the European Union agreed to ban cosmetic testing on animals in 2009, with a ban on products still tested on animals being introduced by 2014. News reports say France is the main reason behind the delays, with the French cosmetics industry allegedly exerting pressure on the government. [22]

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 claim that their products are not tested on animals, despite using one or more of the aforementioned 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, [23] 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. [24]

Although the British Home Office stopped giving licences to test finished cosmetic products in 1998, a raid on a laboratory in 2004 revealed that, due to a legal loophole, the LD50 test is still used on every batch of botox "anti-wrinkle" preparations. [25] Botox is derived from a toxin so potent that .000000000004 g is lethal to a grown human being. Because botox treatments are used for non-cosmetic purposes in the treatment of certain muscle disorders, it is not bound by the regulations specific to cosmetic testing. [26]

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, whch 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.

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.

Alternatives to animal testing

Template:Animal liberation movement Animal-rights and animal-welfare supporters, 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" are principles that govern the use of animals in research in many countries:

  • Reduce: The minimum number of animals to complete the study effectively must be used.
  • Replace: The alternatives to animal testing that have been proposed so far must be explored and developed.
  • Refine: The procedures performed on animals should cause the least amount of harm possible while still maximizing their efficacy so that they will not need to be repeated.

In the United States, compliance is monitored by the Institutional Animal Care and Use Committee (IACUC), and permission and funding to complete research are contingent upon adherence to these rules. In countries where these are not mandated by law, many research institutions comply voluntarily.

There are a number of scientific studies and institutes that are researching alternatives to animal tests. However, opponents say these facilities have been set up to perpetuate what they see as the myth that animal experiments are necessary for human health, and to reassure the public that steps are being taken to find alternatives. [27][28] They say that these institutes are funded with what they say are trivial amounts of money by businesses with a vested interest in the continuation of animal experiments. [29][30]

The two major alternatives to animal testing currently in development are computer simulations and cell culture techniques. Computer simulations at present are limited by the information that has been gathered by animal models and have yet to be designed in such a way that they can be used in the laboratory setting to make predictions about drug reactions. Cell culture techniques, on the other hand, have shown a great deal of promise. Hepatocytes have been cultured into strains that, in the proper medium, can function almost 50% as well as in vivo hepatocytes. Myocardial cells will beat in vitro. Keratinocytes function at up to 80% capacity in some in vitro conditions.

Institutes researching alternatives to animal testing are:

See also

References

Further reading

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