The importance of animal experiments for research
Animal Experiments in Research
Last update: February 2014
Contact: Thorsten Galert
I. The importance of animal experiments for research
Number of laboratory animals: Germany and Europe
Animal experiments are conducted, inter alia, to investigate physiological processes, develop products and therapeutic techniques and verify product safety.
The number of laboratory animals is steadily increasing. For the period 2000 - 2010 the German Animal Welfare Report (see Module Animal Welfare Report) documents an increase in the total number of the vertebrates used for experiments and other scientific purposes from 1 825 215 to 2 856 316 animals. The currently latest data for 2012 record a further increase to 3 080 727 laboratory animals, which means an increment of 5.8 percent compared with the previous year (2 911 705 laboratory animals had been registered in 2011). The main reasons for this increment are the increased use of animals in basic biological research (11.8%) and in quality testing of medical products (2.6%). In contrast, the number of animal experiments carried out in toxicological examinations or other kinds of safety testing has been reduced (4.6%) as well as in research and development of products and devices used for human medicine, dentistry and veterinary medicine (8.8%).
According to information provided by the European Commission (COM Report) (see Module COM Report), more than 12 Million animals were used in 2008 for scientific experiments in the EU member states. This amounts to a small reduction compared to 2005 (12.1 Million animals) although meanwhile two more member states (Bulgaria and Romania) had been admitted to the EU.
Mice and rats together make up the largest group of laboratory animals both in Germany and in Europe (ca. 87%), fish are in second place (ca. 5%) and rabbits are in third place (3%). Non-human primates (see module basic research on primates in Bremen) represent 0.05% of the laboratory animals. Since 1991 great apes (chimpanzees, gorillas, orangutans) (see module human rights for great apes) have no longer been used for experimental purposes in Germany.
Like in 2002, no experiments were performed on apes in 2005 in any of the member states of the European Union. Data are not yet available for the following period.
In various areas (for example in toxicological tests) the numbers of laboratory animals are declining. In fundamental biology studies, however, the number of animal experiments has been on the rise again for some years now. This increase is attributable in particular to the growing use of transgenic mice (see module transgenic mice). The biggest share of laboratory animals (ca. 45%) is used for research, development and quality control in human medicine, veterinary medicine and dentistry.
Animal experiments can be replaced with alternative methods (see module Alternative Methods) in a variety of areas. For example, numerous experiments are currently performed on cell cultures. By way of differentiation from experiments on living organisms (in vivo) such "test tube" methods are referred to as in vitro. Computer simulations may also serve as a substitute for the use of laboratory animals, since they help to predict how substances will act on the body. The extent to which alternative methods may replace animal experiments in the near future is a matter of some controversy. At least in the field of cosmetics research (see module Cosmetics Research) it is envisaged that safety testing on animals will be completely replaced by alternative test methods. Researchers point out, however, that even in the future it will not be possible to entirely do away with animal experiments - especially when it comes to testing pharmaceutical products: the complexity of an intact organism is necessary in order to verify all the effects of a substance. In the fields of neurobiological fundamental research and of research in infectious diseases, for instance, research with non-human primates (see module Weatherall Report on the Use of Non-human Primates in Research) is still irreplaceable at the current moment, according to several researchers.
Applicability of the results of animal experiments
It is only since the advent of the modern era (see module Modern Era) that animal experiments have been conducted on a significant scale. Since then a broad-ranging debate has raged on the acceptability of animal experiments. From the very outset of the debate, opponents of animal experiments have asserted that the insights yielded by animals cannot be applied to humans and are therefore largely useless. This criticism is directed both at the findings of basic research (e.g. the "mouse model") and at the results of drug tests performed on animals (see Section II). At issue was - and still is - the question of whether different species (such as human and mouse) react to the same substances in the same way on account of the structural and functional similarity of many organs or whether the effect of substances on organisms is more heavily species-specific. Were the latter to be the case, animal testing of substances would, for example, offer only an illusory sense of safety. History lends support to both standpoints: on several occasions the results of animal experiments have misled scientists into formulating incorrect research hypotheses (e.g. in research into poliomyelitis (polio) (see module Poliomyelitis) or lulled them into a false sense of security when testing product safety (as in the case of Contergan (thalidomide)) (see module Contergan). In other cases the effects observed in animal experiments did prove to be applicable to humans. The German Research Foundation (DFG), the central self-governing organisation that promotes research in Germany, estimates that animal experimentation can predict "desirable and roughly 70% of undesirable effects on humans" (DFG (2004): Tierversuche in der Forschung. Bonn: Lemmens Verlags- und Mediengesellschaft, 2004: 18).