Trends in the use of animals and non-animal methods over the last 20 years.

Despite the importance of the animal testing issue, there has been little presentation in the scientific literature of the trends in animal use. This is crucial to resolve, particularly if we are to measure the impact of initiatives to reduce and replace animal experiments that were recently announced in Europe and the USA. For the first time, the number of animals used between 2002 and 2022 are presented for the EU, key animal-using countries in Europe (the UK, France and Germany), and North America (the USA and Canada). Animal testing is on a slow decrease in the EU, 11% in the last 20 years, but animal use in the UK, France and Germany is at similar levels as it was in 2002. Notably there has been a decrease in the production of genetically altered animals in the UK and a decrease in regulatory testing in the EU. Animal use in Canada has been steadily growing, and figures for the USA are still incomplete as laboratory-bred rodents and some other species are not counted. However, globally, the use of non-animal methods in biomedical research is increasing exponentially; this accelerated in the mid-2010s. The UK appears to be the leader in this field. The technological, regulatory, political and economic factors that might explain these trends are discussed.