Scientific testing on living animals hit a 10-year low last year, Home Office figures show.

In total, 3.52 million procedures were carried out in 2018, down 7% from 2017.

Around half (1.8m) of the procedures in England, Scotland and Wales were experimental, with more than half (56%) carried out for basic research - most commonly focusing on the immune system, the nervous system and cancer.

The other 1.72m were for the creation and breeding of genetically altered animals, which is down by 10%.

The majority of procedures (93%) were done on mice, fish and rats, which have been the most used animals for the past decade, but the number of rats used fell by 27%.


The number of experimental procedures on birds increased from 130,000 to 147,000.

Specially protected species - cats, dogs, horses and primates - accounted for 1% (18,000) of experimental procedures.

The number of experiments with cats decreased by 20%, but the number using dogs rose by 16%, and the number on primates increased by 8%.

Since 2014, the Home Office, which is responsible for regulating animal experiments, has counted the number of procedures conducted on animals, not the number of animals that were involved.

It has classified testing according to the amount of suffering it causes and said it considered more than two-fifths (40.2%) to be sub-threshold, meaning the creature's discomfort was measured as less than a needle prick.

Nearly 40% (38.9%) of last year's procedures were assessed as mild, 14.7% moderate and 3.6% severe.

Ten organisations account for nearly half of animal research in Britain, according to data from Understanding Animal Research, which promotes openness about animal research.

The 10, which include some of the country's main universities and institutes, carried out 1.69 million procedures, nearly half of last year's total, more than 99% of them on rodents or fish.

All have said they are committed to replacing animals where possible, reducing the number of animals used per experiment, and refining the experience of the animals to improve welfare.

Frances Rawle, director of policy, ethics and governance at one of the institutes involved, the Medical Research Council, said: "The use of animals in medical research remains essential for us to develop new and better treatments and to understand the biology of disease.

Professor Julian Downward, associate research director at the Francis Crick Institute, said: "While we use alternatives wherever possible, living animals are incredibly complex and there are many processes we simply can't simulate."