The Home Office has released the statistics for animal use in science in Great Britain for 2022, with data showing that the total number of procedures was down almost 10% compared to 2021. Overall animal research activity is at its lowest level since 2002. This could reflect a combination of factors, from a shift in research priorities and funding to an increasing focus on the use of non-animal alternatives.

There were a total of 2.76 million scientific procedures involving living animals completed in 2022 (this is usually higher than the number of animals used, as under certain conditions an animal may be reused).

1.51 million (55%) were experimental procedures, whilst 1.25 million procedures (45%) involved the generation or breeding of Genetically Altered (GA) animals.

96% of all procedures used mice, fish, birds or rats. The species distribution in experimental procedures is: 59% mice, 14% fish, 12% rats, 9% birds, 5% other species and less than 1% specially protected species. Procedures for generation of GA animals involved 86% mice, 13% fish, 0.6% rats and birds and 0.4% other species. The specially protected species are non-human primates, horses, dogs and cats and applications to work with these species undergo additional scrutiny.

Animals were used in experimental procedures for the following purposes: around half of procedures (53%) were for basic research, most commonly focusing on the nervous system, the immune system, and cancer.  21% of experimental procedures were for regulatory purposes, a similar figure to 2021. These procedures include safety and efficacy testing for new drugs and treatments before they are used in human clinical trials. 24% were for applied research, a fall from 27% in 2021. Applied research attempts to address diseases through prevention and development of treatments, most commonly to tackle animal diseases and disorders, human cancer, infectious disorders and human neurological disorders.

All scientific procedures involving vertebrate animals (other than humans) and cephalopods must be performed under license and the use of animals must be recorded, together with an assessment of the severity levels, and published every year in accordance with the Animals (Scientific Procedures) Act 1986 amended 2012.

Dr Mark Downs CSci FRSB, chief executive of the Royal Society of Biology, commented:

“Animal research is an important area of the life sciences, which contributes to our knowledge of animal physiology and potential treatments for disease in humans and other animals.

“From the genetic underpinning of ageing and metabolic diseases or the complex mechanisms underlying neurodegenerative disorders, animal experiments provide essential clues and evidence, alongside non-animal alternatives, such as human cell-based systems, organ-on-a-chip and computational methods.

“The UK has a strict regulatory system that requires scientists and laboratory staff to show competence before they can perform animal experiments. Each research project is individually assessed and licensed by the regulator, and reviewed by local ethical review bodies, before it can proceed.

“As a country, we have been leaders in laboratory animal welfare and culture of care, a track record we must strive to maintain. The animal research community continues to drive the development and update of innovative solutions to replace, refine and reduce the use of animals in research and testing (3Rs), under the leadership of the National Centre for the 3Rs.

“The Royal Society of Biology supports the use of animals in research when no alternatives are available, and is committed to promoting openness and transparency in reporting the use of animals for scientific purposes”.

Professor Clare Stanford FRSB, chair of the RSB Animal Science Group, commented:

“The assembly and publication of these data is a testament to the UK’s commitment to openness and transparency in respect of the use of animals in scientific procedures.

“Research that aims to develop non-animal alternatives is making important and welcome progress and their use is becoming a realistic option in some fields of research. In other fields, such as mental health and dementia, where the use of animals is still unavoidable, the aim to reduce the use of animals is driven by continual improvement in the design of experiments, to ensure the animals are not used unnecessarily, as well as refinements of the experimental procedures, which minimise their impact on the animals’ welfare.  

“Both the numbers of animals used for experimental purposes and the total number of procedures that were carried out are lower than the year before. Whereas this pattern is consistent with a commitment to the 3Rs, especially ‘reduction’, it is important to ensure that these changes do not reflect a decline in research outputs that are beneficial to humans and other animals, which would undermine UK’s status as a world leader in biomedical research.”

For context, a procedure is defined as anything that causes pain, suffering, distress or lasting harm equivalent to, or greater than, the insertion of a hypodermic needle in accordance with good veterinary practice (for example a vaccination). This is the threshold. Even if the genetic modification causes no harm (i.e. is below threshold) breeding natural mutants or genetically engineered animals is counted as a procedure.

The actual severity of regulated procedures has been recorded since 2014. The actual severity of experimental procedures on animals was 96% non-recovery (where the animals does not wake up after anaesthesia), sub-threshold, mild or moderate; only 4% were severe.

The actual severity of procedures for the generation and breeding of GA animals was 99% non-recovery, sub-threshold, mild or moderate; only 1% were severe. 1.14 million (91%) procedures used GA animals with no harmful phenotype.

Procedures are classed as “sub-threshold” when they do not cause suffering above the threshold for regulation. Mild severity is the equivalent of an injection or having a blood sample taken, moderate severity is greater than transient pain (for example surgery under anaesthesia followed by painkillers during recovery), severe suffering is something that we would not wish to endure (for example a heart attack).

Animal research in the UK is strictly regulated according to the policy and operations of the Animals in Science Regulation Unit.

The Society supports the efforts of the scientific community to replace, reduce and refine animal experiments (3Rs) and also advocates transparency in reporting the justification and outcomes of research involving animals. Members of the public can access a summary of each licensed research project when they are published on the Home Office website.

The Society discusses issues related to animal science through its special interest group the Animal Science Group, and is involved in informing policy for the advancement of science and animal welfare as a member of the UK Bioscience Sector Coalition.