Balancing harms and benefits

At Manchester, we follow legal guidelines to assess the balance between medical progress and suffering of animals in research.

By law, an assessment of the balance between harms and benefits must underpin any licensed animal research.

The assessment weighs the potential benefits of a research project for humans and animals, against the harms that are likely to be caused to the animals involved. This analysis is carried out by a competent authority or an ethics committee.

Benefits of our research

Explore our case studies pages to discover the benefits of research involving animals at Manchester, covering health and the area of replacement, reduction and refinement.

Assessing and monitoring harm

Any activity that can cause an animal pain, suffering or distress is referred to as a ‘procedure’. A procedure can be as mild as an injection or as severe as a surgical intervention where mortality can, in rare cases, occur. All experiments involve procedures, but not all procedures are experiments.

All procedures are classified as 'sub-threshold', ‘mild’, ‘moderate’, ‘severe’ or ‘non-recovery’ based upon the degree of pain, suffering, distress or lasting harm that the animal is expected to experience. The expected severity of a procedure is currently determined during the licence application.

Levels of severity experienced by animals

The law defines the levels of severity animals experience as:

  • Subthreshold: where the animals do not suffer
  • Mild: causes short-term mild pain, suffering or distress
  • Moderate: causes short-term moderate pain, suffering or distress or long-lasting mild pain, suffering or distress
  • Severe: causes short-term severe pain, suffering or distress, or long-lasting moderate pain, suffering or distress
  • Non-recovery: the animal is placed under general anaesthetic before the start of the procedure and is humanely killed without ever regaining consciousness

Most research involving animals at Manchester is either mild or subthreshold. The graph below shows the breakdown of licensed research at Manchester according to 'sub-threshold', ‘mild’, ‘moderate’, ‘severe’ or ‘non-recovery’ bandings.

Chart: severity levels of our animal research