Humane endpoints define the point at which experimental animals are euthanized to prevent unnecessary suffering, and their earlier and more consistent application is a key lever for reducing laboratory animal welfare harm.
Laboratory animals subjected to experiments without well-defined humane endpoints may experience prolonged suffering that serves no scientific purpose. Death as an experimental endpoint is rarely scientifically necessary and causes maximal welfare harm. Institutional Animal Care and Use Committees play a critical role in reviewing and approving humane endpoint criteria, but their effectiveness varies. Training researchers to recognize early pain and distress signs enables intervention before suffering becomes severe. Developing validated species-specific welfare assessment tools improves the consistency and objectivity of endpoint decisions. Advocacy for rigorous humane endpoint requirements in institutional and regulatory guidance reduces aggregate laboratory animal suffering substantially.