The application of humane endpoints and humane killing methods in animal research proposals: A retrospective review

Refinement refers to the use of methods that help to minimise animal suffering in the laboratory. Research in this area has increased significantly over the past two decades. However, the extent to which refinements are applied in practice is uncertain. To provide an indication of the implementation and awareness of refinements, we reviewed the experimental techniques for 684 surgical interventions described in 506 animal research applications sent to the German competent authorities for approval in 2010. In this paper, we describe and discuss the appropriateness of the proposed humane endpoints and killing methods. We found that, when the investigators included humane endpoints in their application, these were often lacking in detail and/or were to be implemented at a late stage of suffering. In addition, the choice of method to kill the animals could be improved in the majority of the applications. We provide recommendations for future improvements, based on the recent literature. To ensure scientific rigour, avoid needless animal suffering and enable an accurate harm-benefit analysis, animal researchers have to be knowledgeable about refinement methods and apply them effectively. To assess compliance and ensure that only those studies in which potential benefits outweigh the harms are carried out, reviews such as ours - as well as retrospective assessments of actual harms and benefits - should be conducted widely and regularly, and the findings should be published.