Facts and figures

Once a year, the Home Office releases the statistics on the numbers of procedures that have been completed during the previous year and the severity of those procedures.

The number of procedures carried out as part of research programmes in establishments owned by the Medical Research Council (MRC) reported to the Home Office for 2022 was 136,732. This is around 5% of the total of 2.7 million scientific procedures reported to the Home Office for that year. The number of scientific procedures by species and severity (severity categories are described in the annual statistics of scientific procedures on living animals, Great Britain (PDF, 981KB)) can be found in the tables below. Breeding of genetically altered animals accounted for 59% of all procedures carried out.

Scientific procedures on living animals in MRC institutes, numbers by species, 2022
Species Number Percentage
All procedures 136,732 100
Mouse 136,673 >99
Rat 6 <1
Old world monkey (macaque) 53 <1
Fish 0 <1

Explanation of severity levels

Scientific procedures on living animals in MRC institutes, numbers by severity, 2022
Severity Number Percentage
All procedures 136,732 100
Sub-threshold 87,558 64
Non-recovery 1,620 <1
Mild 35,711 26
Moderate 7,050 5
Severe (includes animals found dead) 4,793 4


When a procedure was authorised under a project licence but did not actually cause suffering above the threshold of regulation, meaning was less than the level of pain, suffering, distress or lasting harm that is caused by inserting a hypodermic needle according to good veterinary practice.


When the entire procedure was carried out under general anaesthesia without recovery.


Any pain or suffering experienced by an animal that was, at worst, only slight or transitory and minor so that the animal returns to its normal state within a short period of time.


The procedure caused a significant and easily detectable disturbance to an animal’s normal state, but this was not life threatening. Most surgical procedures carried out under general anaesthesia and with good post-operative analgesia (meaning pain relief) would be classed as moderate.

Severe (includes animals found dead)

The procedure caused a major departure from the animal’s usual state of health and wellbeing. This would usually include long-term disease processes where assistance with normal activities such as feeding and drinking were required, or where significant deficits in behaviours or activities persist. It includes animals found dead unless an informed decision can be made that the animal did not suffer severely prior to death.

MRC-funded research grants

Currently, 31% (data accessed 2 May 2023) of active MRC-funded research grants involve the use of animals licensed under the Animals (Scientific Procedures) Act 1986.

Research ranges from fundamental studies on how normal biological systems work to studies used to investigate possible treatments for human or animal disease.

Summary information on all funded projects may be found on Gateway to Research.

All MRC-funded active research grants

Active MRC-funded research grants involving the use of animals, May 2023
Species Percentage
Mouse 78
Rat 10
Pig 4
Fish 1
Non-human primate 1
Other animals 5

Around 5% of our currently live awards involve less commonly used species categorised in the above table as ‘other animals’. These animals are highlighted below:

Active MRC-funded research grants involving less commonly used species, May 2023
Species Percentage
Sheep 0.8
Bird 0.8
Amphibian 0.5
Gerbil 0.5
Guinea pig 0.3
Cow 0.3
Dog 0.3
Hamster 0.8
Other 0.8

Information on 3Rs impacts in MRC-funded research grants can be found on MRC 3Rs webpages.

Last updated: 17 August 2023

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