Methods which improve animal welfare

Our goals are to ensure that each individual animal within an experiment is experiencing the minimum pain, suffering, distress or lasting harm that is compatible with a meaningful result. Both direct harms (such as pain following an injection) and associated harms (such as altering a social group to equalise experimental group sizes) need to be considered.

Any departure from normal conditions, routine and treatment could contribute to the overall impact of the procedure on the animal. The duration of an experiment is also considered. Examples of refinement include using using the least invasive methods for any surgery with appropriate anaesthetics and analgesics, and placing limits on the number of times an individual animal may experience a particular stress. The Babraham Campus Animal Usage Guidelines are reviewed regularly by vets and the AWERB ethical review committee. These advise on certain procedures such as dosage routes, volumes and frequencies, and follow a variety of published good practice guidelines.

The ultimate aim is the continual improvement of an experimental model with the minimal departure from normality. Advance consideration of any likely adverse events, such as a drug reaction or an infection, together with definition of humane end points is essential.


Refinement Examples

  • The default method to collect tissue samples to confirm the genetic make-up of mice was changed from using the tail tip to the ear.
  • Welfare advantages include a lack of sensitivity in the ear and its limited functionality compared to the tail tip.
  • Environmental enrichment is compulsory in animal cages and is varied to suit the occupants. For example, refuges such as opaque tunnels and elevated rafts are provided, the latter also being of value in case of drinking water leaks.
  • Food treats such as seeds may be mixed in bedding to provide interest and all animals are provided with materials to build nests.