Animal research

Annual statistics

The University reports the number of animals that are used in research by species each year.

A 'regulated procedure' is one that:

  • Is carried out on an animal of a protected species
  • Is for a scientific purpose
  • May cause the animal a level of pain, suffering, distress or lasting harm equivalent to, or higher than, that caused by inserting a hypodermic needle in line with good veterinary practice.

All living vertebrates, excluding humans, and cephalopods, such as octopus, are protected by law. Embryonic and foetal forms are considered 'protected animals' in the last third of gestation, or incubation for egg-laying species. Larval forms of fish and amphibians are protected animals once they are capable of independent feeding. For example, zebrafish larvae become protected five days after fertilisation.

Procedures carried out on animals during early stages of development, before they reach protected status, may also be regulated under ASPA if the animals are kept alive beyond the point at which they become protected.

In 2021, the University carried out 172,100 scientific procedures involving animals. The vast majority of these involved rodents, predominantly mice and rats (69.6%), and fish (26.4%). 

Species Number Percentage
Rodents 119,763 69.6%


Birds 6,132 3.6%
Agricultural species (cattle, sheep, pigs) 558 0.3%
Animals monitored in the wild (sheep, deer) 185 0.1%

These figures are calculated each year based on data from annual returns that are prepared for the Home Office by every Project Licence holder.

2020 statistics

2019 statistics

2018 statistics

2017 statistics

2016 statistics

2015 statistics

2014 statistics


Severity statistics

Each regulated procedure is assigned a severity which describes the animal's experience. Figures for 2021 are available at the link below. Figures for 2022 will be available by end of July 2023.

Severity statistics