Home Office annual statistics of scientific procedures on living animals in Great Britain 2022

The Home Office’s Annual Statistics report that the number of scientific procedures carried out on living animals in the UK in 2022 is 2.76 million. This is a 10% decrease from 3.06 million procedures in 2021. Whilst this decrease is positive, we remain concerned about the number of experimental procedures still taking place using animals, particularly with regards to basic research, where there is no legal requirement to use animals and more scope to explore non-animal research.

Here, we discuss the details of the report and highlight any continuing trends, notable changes, and new insights.

Annual Statistics of Scientific Procedures 2022: headline stats and trends

Great Britain’s statistics record the number of procedures conducted, rather than the total number of animals used in procedures.

In total, 2.76 million procedures were conducted using live animals in Great Britain in 2022, a decrease from 3.06 million in 2021.

This is the lowest number of procedures records since 2002.

Of these 2.76 million procedures, 1.51 million (55%) were carried out for experimental purposes, and 1.25 million (45%) were carried out for the creation and breeding of genetically altered (GA) animals (Figure 1). Compared to 2021, experimental procedures have decreased by 13%, and GA procedures have decreased by 6%.

96% of all procedures used mice, rats, birds, or fish. Mice remain the most common, being used in 59% of experimental procedures, followed by fish in 14% experimental procedures, rats in 12% experimental procedures, and birds in 9% experimental procedures (Figure 2). A similar pattern is followed with animals used for creating and maintaining genetically altered lines of animals, with mice being the most commonly 86% of procedures, fish in 13% of procedures, and rats in 0.5% of procedures. The remaining 0.5% of procedures used domestic fowl, amphibians, sheep and pigs.

Where were animals used?

In experimental procedures, basic research remains the area where the most procedures using animals are conducted at 53%. This is a slight increase from 2021 where 51% of experimental procedures were for the purpose of basic research. The most common research areas within basic research were the nervous system (25%), the immune system (19%) and oncology (12%) (Figure 3). These areas have remained broadly the same since 2014.

Applied research accounted for 24% experimental procedures, a decrease from 27% in 2021. The most common applied research areas were animal diseases and disorders (34%), and human cancer (23%) (Figure 4). Regulatory testing accounted for 21% of experimental procedures, mainly toxicity and other safety testing (55%) (Figure 5). This is very similar to 2021. You can read more about the areas of research under experimental procedures.

All procedures are classified by severity level based on the likelihood of pain, suffering, distress, or lasting harm caused. In 2022, 96% of all experimental procedures were assessed as non-recovery (4%), sub-threshold (20%), mild (46%) or moderate (27%) in severity, with the remaining 4% being assessed as severe (Figure 6). Read more about severity assessments.

Of the 1.25 million GA procedures carried out, 89% were for the maintenance of already established GA lines, and 11% were for the creation of new lines. Of the 143,000 procedures for the creation of new GA lines, 91% were used in basic research with the most common areas being multi-systemic research, the nervous system, oncology, and cardiovascular blood and lymphatic system. The split between maintenance of established lines and the creation of new lines of genetically altered animals is broadly similar to previous years.

91% of these 1.25 million procedures used genetically altered animals that had no harmful phenotypes, meaning that the animals did not appear or behave any differently from non genetically altered animals. This number has been steadily increasing since 2015 which is a positive in terms of animal welfare.

In total, 139 establishment licenses were held during 2022. 2 of these establishments did not have any active project licenses, and there were a total of 2913 project licenses in force overall. Data on the type of establishments (schools, universities, etc) is no longer collected.

Where do we go now?

Whilst a decrease in the number of procedures from the previous year is positive, we remain concerned about the fact that 2.76 million procedures have been conducted using living animals.

We are particularly concerned with the large number of procedures conducted on animals for the purpose of basic research (53%) where there is no legal requirement to use animal research and therefore more scope to explore non-animal approaches. Searching for non-animal methods in basic research is down to the individual researcher to find, evaluate and choose over the use of animals. Whilst the researchers must evidence replacement in their licensing applications under the Animals (Scientific Procedures) Act 1986, it is difficult to know every non-animal approach available and how to combine and apply them effectively and therefore choose them over animal methods and models. It is also difficult for those assessing licensing applications to judge whether the 3Rs have been effectively applied in line with current legislation. If we are to make active strides towards replacing animal use in research and testing There must be improvements in the way applications for animal research licenses are reviewed, and more emphasis on training and support, for researchers and those assessing license applications. In particular, the reporting requirements that show how non-animal methods have been researched and assessed, what alternative approaches exist and why they cannot be combined or adapted for this study which now requires animals. Supporting systems for finding, assessing and utilising non-animal approaches are key to helping reduce the number of animals used in basic research.

We also remain concerned about the large number of animals that are still required to maintain genetically altered lines. Investing more time and funding into developing non-animal methods that can replace genetically altered animals will substantially reduce the number of animals required for genetically altered purposes, and therefore reduce the overall number of animals used for scientific purposes in the UK.

It remains clear that the use of non-animal methods must be accelerated and pushed to the forefront of the conversation. As a world leader in scientific innovation and animal welfare, the British Government must ensure it commits to the reduction, and replacement of animals in research through direct funding and initiatives to help replace animal research. This not only benefits animals but also humans by allowing more relevant, human-based science.

Read the Home Office report on Annual Statistics of Scientific Procedures on Living Animals in Great Britain 2022.