Numbers and types of animals

cagesBritish law protects vertebrate animals such as mammals, fish and birds and these are the animals which are counted by government every year. Most research animals are rodents, followed by fish and birds. Dogs, cats and monkeys together represent two in every 1000 animals used in UK research.

Invertebrate animals such as fruit flies and worms are used in large numbers in research but are not protected by the law or counted.

There were less than four million scientific procedures using animals in 2016 in the UK. The figure was 3.94 million. The number of animals used is slightly less as some animals are used more than once. This does not happen often, and is strictly controlled.

Numbers relate to procedures on animals in Great Britain in 2016:

  • Rats, mice and other rodents, all purpose-bred laboratory species 72%
  • Fish 14%
  • Amphibians, reptiles and birds 7%
  • Primates, horses, dogs and cats, all bred for research, no strays or unwanted pets can be used 0.9%

Chimpanzees, orang-utans and gorillas have not been used in the UK for over 20 years and their use is now banned.

The annual number of animal experiments is now about the same as it was 20 years ago, having gone down substantially between 1988 and 1998, but then levelling off and rising until 2014 when the numbers again fell.

To put the figures into perspective, although the number of animal procedures increased by one million (over one third) in the 12 years to 2009, UK expenditure on biomedical research more than doubled in real terms over the same period.


The recent rises in animal procedures are mainly due to the increased production and use of animals with genetic modifications or defects (many fall into the 'breeding' category). The numbers of genetically normal animals have been quite level this century.

In 2016 there was a reduction of around 5% in the overall number of procedures.

Graph of severity GB 2016

International estimates

Trying to estimate the numbers of animals used in research worldwide is difficult because many countries do not provide comprehensive statistics. However, we know that the major centres for research are the USA (about 11 - 25 million animals), EU including the UK (about 12 million animals), and Canada (about 3 million animals). Unfortunately Australia, China, and Japan are the only Western countries that do no report their research statistics.

Other countries that report annual research statistics include Israel (about 335,000 animals), Norway (about 5.5 million animals), and Switzerland (about 600,000 animals).

Further information

Please see our other pages that break down the numbers of animals used in UK research according to species and areas of research, and explore the major contribution of more and more GM animals to advances in science and medicine.

The detailed annual government statistical report from the Home Office is also available online.

Last edited: 13 July 2017 11:37