|Description||Around 50–100 million vertebrate animals are used in experiments annually.|
|Subjects||Animal testing, science, medicine, animal welfare, animal rights, ethics|
Animal testing, also known as animal experimentation, animal research and in vivo testing, is the use of non-human animals in experiments that seek to control the variables that affect the behavior or biological system under study. This approach can be contrasted with field studies in which animals are observed in their natural environments or habitats. Experimental research with animals is usually conducted in universities, medical schools, pharmaceutical companies, defense establishments and commercial facilities that provide animal-testing services to industry. The focus of animal testing varies on a continuum from pure research, focusing on developing fundamental knowledge of an organism, to applied research, which may focus on answering some question of great practical importance, such as finding a cure for a disease. Examples of applied research include testing disease treatments, breeding, defense research and toxicology, including cosmetics testing. In education, animal testing is sometimes a component of biology or psychology courses. The practice is regulated to varying degrees in different countries.
It is estimated that the annual use of vertebrate animals—from zebrafish to non-human primates—ranges from tens to more than 100 million. In the European Union, vertebrate species represent 93% of animals used in research, and 11.5 million animals were used there in 2011. By one estimate the number of mice and rats used in the United States alone in 2001 was 80 million. Mice, rats, fish, amphibians and reptiles together account for over 85% of research animals.
Most animals are euthanized after being used in an experiment. Sources of laboratory animals vary between countries and species; most animals are purpose-bred, while a minority are caught in the wild or supplied by dealers who obtain them from auctions and pounds. Supporters of the use of animals in experiments, such as the British Royal Society, argue that virtually every medical achievement in the 20th century relied on the use of animals in some way. The Institute for Laboratory Animal Research of the United States National Academy of Sciences has argued that animal research cannot be replaced by even sophisticated computer models, which are unable to deal with the extremely complex interactions between molecules, cells, tissues, organs, organisms and the environment. Animal rights organizations—such as PETA and BUAV—question the need for and legitimacy of animal testing, arguing that it is cruel and poorly regulated, that medical progress is actually held back by misleading animal models that cannot reliably predict effects in humans, that some of the tests are outdated, that the costs outweigh the benefits, or that animals have the intrinsic right not to be used or harmed in experimentation.
The terms animal testing, animal experimentation, animal research, in vivo testing, and vivisection have similar denotations but different connotations. Literally, "vivisection" means "live sectioning" of an animal, and historically referred only to experiments that involved the dissection of live animals. The term is occasionally used to refer pejoratively to any experiment using living animals; for example, the Encyclopædia Britannica defines "vivisection" as: "Operation on a living animal for experimental rather than healing purposes; more broadly, all experimentation on live animals", although dictionaries point out that the broader definition is "used only by people who are opposed to such work". The word has a negative connotation, implying torture, suffering, and death. The word "vivisection" is preferred by those opposed to this research, whereas scientists typically use the term "animal experimentation".