What are humane endpoints, and how do they relate to IACUC protocols?

• A. Predefined criteria for terminating an animal's involvement to terminate a study regardless of distress.
• B. The point at which an experiment must be terminated for all animals regardless of condition.
• C. Predefined criteria for terminating an animal's involvement in a study to prevent unnecessary pain; they are required in protocols to ensure welfare.
• D. A list of analgesic doses to be used in all studies.

Answer: (C)

Humane endpoints are predefined criteria that tell you when an individual animal should be removed from a study to prevent or minimize pain and distress. In IACUC protocols, investigators specify these endpoints so that actions—such as providing analgesia, offering supportive care, or euthanizing the animal—are taken promptly when signs or measurements reach certain thresholds. This creates a clear, approved plan for safeguarding welfare and ensures consistent decision-making across the study. The concept focuses on the welfare of each animal rather than terminating the entire study; it’s not simply a list of analgesic doses. Humane endpoints are about stopping involvement when suffering becomes unacceptable, and they must be described in the protocol to satisfy welfare requirements and regulatory oversight.