The importance of animal experiments for research
Animal Experiments in Research
Last update: March 2015
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.
Statistical data gathered by the German Federal Ministry of Food and Agriculture (BMEL) (see Module Statistical data on animal experiments in Germany) concerning the number of animal experiments shows that the total number of vertebrates used annually between 2003 and 2012 has continually increased from 2 212 376 to 3 080 727 animals. The most recent numbers for 2013 document a slight decline compared to the previous year by 2.7% to 2 997 152 laboratory animals. The BMEL explains this decline by pointing out the reduction of 7.6% in the number of animals used for toxicological investigations. With a share of 40% of the total number of laboratory animals, most animals in 2013 were used in biological basic research. In contrast to the declining trend, even more animals have been used in this field in 2013 compared to the previous year. The main reason for this increase is the growing use of transgenic mice (see module transgenic mice) which meanwhile represent 30% of the total number of laboratory animals.
According to information provided by the European Commission (see Module Statistical data on animal experiments in the EU), almost 11.5 million animals were used in 2011 for scientific experiments in EU Member States. Compared to the data for 2008 (12 million animals), this amounts to a decline of 4.2%. Mice and rats together make up the largest group of laboratory animals both in Germany (84% in 2011, 86% in 2013) and in Europe with 75% (2011); in Germany fish are in second place (7% both in 2011 and 2013) and rabbits in the third place (3% both in 2011 and 2013). In EU Member States, non-human primates (see module Basic research on primates in Bremen) represented 0.05% of the laboratory animals. Since 1991 great apes (see module human rights for great apes) (chimpanzees, gorillas, orangutans) have no longer been used for experimental purposes in Germany. Neither have experiments on apes been conducted in the Member States of the European Union during the period of 2002-2011. Data are not yet available for the subsequent period.
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).