Severity Statistics

The statistics for animal use are based on animals used in regulated procedures.

The definition of a regulated procedure from the legislation is any "procedure applied to a protected animal for a qualifying purpose which may have the effect of causing the animal a level of pain, suffering, distress or lasting harm equivalent to, or higher than, that caused by the introduction of a needle in accordance with good veterinary practice."

For each procedure a 'severity' is assigned which describes the experience of the animal as categorised below:

• Sub-threshold. These procedures may result in below threshold severity. For example, the procedure was expected to cause pain or suffering equal to, or higher than, that caused by inserting a hypodermic needle but the actual experience was in fact less than this. Examples of this include:
  • The breeding of genetically altered animals under project licence authority but without a harmful phenotype
  • Dispensing medication in food where the animals ate normally and suffered no ill-effects
• Mild. These procedures may cause short-term mild pain, suffering or distress and/or minor changes in well-being or condition. Mild procedures can include:
  • Anaesthesia
  • Non-invasive imaging such as a MRI scan
  • Short term social isolation
  • Taking a blood sample
• Moderate. These procedures may cause short-term moderate pain, long-lasting mild pain, suffering or distress. They can result in a moderate impairment to well-being. Examples include:
  • Surgery under general anaesthetic
  • A modified diet
  • Exposing the animal to something from which they would normally flee
• Severe. These procedures are where it is likely that the animal will experience severe pain, long-lasting moderate pain, suffering or distress and severe impairments to its well-being or general condition. Examples include:
  • Any test where fatalities are expected
  • Testing a device that could cause pain or death were it to fail
  • Breeding animals with genetic disorders that are expected to result in severe and persistent impairment of general condition
• Non-recovery. Where the animal is placed under general anaesthetic before the start of a procedure and is humanely killed without regaining consciousness.

In 2025, the University carried out 131,103 scientific procedures involving animals. The actual severities are detailed in the table below.

Archive 

Severity statistics 2024

Severity statistics 2023

Severity statistics 2022

Severity statistics 2021

Severity statistics 2020

Severity statistics 2019

Severity statistics 2018

Severity statistics 2017