Relevant legislation, including guidance on methods of humane killing should be consulted well before animal studies start, because the proposals may be regulated and may involve personnel training and purchase of equipment or chemicals. Efforts must also be made to ensure that the method used is the most refined for the particular species, without compromising the study aims or parameters to be measured. Any deviation from regulatory standards (e.g. those described in Annex IV of the EU Directive 2010/63) must be described and justified, along with the likely effects on the animals and measures to minimise these.
Two scenarios for humane killing should be discussed:
- The primary method of humane killing, to be used when animals are no longer required, if re-homing or release is not an option
- A method for emergency killing, preferably one which can be performed by any competent member of staff outside normal working hours, even if they have little experience with the species concerned
These two methods may or may not be identical.
These considerations should also extend to field studies, and should include a discussion of the procedure to be followed if a researcher encounters sick or injured wildlife that are not a part of the population being studied.