The performance of surgical procedures or other invasive tests on animals for experimental purposes.

Most experiments are carried out on specially bred mice and rats. Less than 1 per cent is done on cats, dogs, non-human primates, farm animals, frogs, fish and birds.

Universities in Britain are responsible for less than one-fifth of animal experiments; commercial concerns and government institutions are responsible for most of the rest. Tests on cosmetics account for less than 1 per cent of all animal work, but are performed because such materials are often applied with great frequency – and for a long time – to the skin of adults and infants.

There is widespread concern about vivisection because of the potential for cruel treatment of animals. Consequently tissue cultures and computer models are increasingly used where possible instead of live animals. There is, however, a limit to the extent to which infection, cancer, or drug safety can be investigated on cultures of tissue cells and there is no drug which has not been tested on animals, while most surgeons practice their craft on animals to perfect procedures on humans. Strict licensing of premises and individuals by government seeks to minimise unnecessary or improper use of animals according to law.