UK Animal Research Statistics

The United Kingdom reports a wealth of information every year on its use of animals in research. Every animal procedure must be categorised according to the overall purpose (and specific disease area or regulatory purpose if relevant), the genetic status of the animals and the severity of the procedure. Great Britain (England, Scotland and Wales) conducts approximately 99.5% of procedures, which are regulated by and reported by the UK Home Office. Northern Ireland conducts the remaining 0.5% which is regulated and reported by the Department of Health in Northern Ireland. Use the links below to jump to the relevant statistics.

Animal Research in the United Kingdom

Different colours represent changes to the counting method in 1987 and 2014.
Trend over time in animal experiments in the UK. Click to Enlarge.

Every year the Home Office releases the statistics on animal research in Great Britain (Northern Ireland released separately) for the preceding year. In 2017, the total number of procedures on animals was 3.79 million, down 4% from the  3.94 million in 2015.

The total number of animals was slightly lower, at 3.72 million, as some animals were used for more than one procedure*. In 1987 the UK changed the way in which it counted animals, from the total number of animals to the total number of procedures. There was a further, smaller change to methodologies in 2014. The statistics for Northern Ireland are not included and we have provided more details at the bottom of the page (22,214 procedures in 2016).

*The total number of animals excludes those animals first used in a previous year, which underwent a procedure in the current year, in order to prevent double counting of animals between years.

The last few years have seen the number of Genetically Altered animals (mainly GA mice) being bred rising as a proportion of all studies; this accounts for 50.2% of all procedures (in 2017).Other common uses included basic research (27.5%), regulatory purposes (13.3%) and translational/applied research (8.5%).


Looking at the species used we can see, mice, rats, birds and fish account for over 96% of all procedures on animals in Great Britain. Dogs and cats account for 0.11% and primates account for around 0.08%. Invertebrates such as fruit flies and nematode worms are widely used by researchers but are not covered by the Animals (Scientific Procedures) Act and are thus not included. The only invertebrate included in the statistics are cephalopods, though none have been used in recent years.

Procedures on animals in Great Britain for research in 2017. Click to Enlarge

The UK statistics include retrospective reporting of suffering. Rather than just submitting licence proposals to the Home Office that include estimated levels of suffering, the researchers now have to report on what was actually seen (using a variety of measures). Unfortunately, the statistics put these in two separate tables (Table 3 and 8). We have combined them to get severity for all procedures in 2016 – see definitions on page 20). It shows that 81.8% of procedures are sub-threshold, non-recovery or mild, and involved minimal pain or suffering for the animals. 14.5% of studies were moderate (16% in 2016) and 3.6% were severe (3.9% in 2016). So overall the level of severity has decreased in 2017. Also of note in the severity data is the rising proportion of sub-threshold experiments in the creation/breeding of genetically modified animals from 45% in 2014, to 55% in 2015, to 65% in 2016, and now to 74% in 2017 suggesting improvement in methods.

Severity of animal research in Great Britain in 2017

It is also important to realise that no animal research or testing was done for:

  • Tobacco products (banned in 1997)
  • Cosmetic products or ingredients (banned in 1998)
  • Household products (banned in 2015)
Graph - Milestones in Animal Research
Image by Understanding Animal Research

When we look at the other uses of animals in the UK we see that those killed for medical research (and the huge benefits that go with it) are far outweighed by the numbers of fish and chickens eaten, and even by the number of birds and other wildlife killed by domestic cats.

Finally, it is worth remembering the huge benefits brought about by animal research. Here are some annual figures of treatment used that were developed through animal research.


Table sources:

UK Statistics Sources:
Speaking of Research Report on statistics:

Home Office reports 2001-2017:

Animal Research in Northern Ireland

In Northern Ireland, animal research statistics are compiled by the Department of Health, Social Services and Public Safety in Northern Ireland (as opposed to the UK Home Office, as in England, Scotland and Wales).

Animal research in Northern Ireland accounts for much less than 1% of the total animal research in the UK. In 2016 the number of procedures was 22,214, down 1% from 2015.

Click to Enlarge

Since the number of procedures involving the creation and breeding of GM animals is much lower than in the UK (and these are often sub threshold), the proportion of sub threshold procedures is much lower than the rest of the UK, though this proportion is rising. The number of severe procedures is similar to the rest of the UK, but there is a higher proportion of moderate severity procedures.



Animal Research statistics of Northern Ireland, 2005-2016: