Reducing Animals' Pain and Distress

The Animal Welfare Act requires pain and distress experienced by research animals to be minimized where possible (7 U.S.C. § 2143 (a)(3)(A)-(C) (2022)).  Therefore, it's critical for any personnel working with animals to recognize and assess animal pain and distress. This allows them to manage and minimize or eliminate the animals' pain and distress quicker. The resources below provide information on tools used to recognize and assess pain in various animal species. 

Although the terms analgesia and anesthesia are often confused with one another, they have two different intentions when used. Analgesia is the relief of pain without the loss of consciousness or sensation using analgesics (e.g., Aspirin, Carprofen, etc.). Anesthesia is the loss of physical sensation with or without loss of consciousness using anesthetics (e.g., Ketamine, Propofol, Isoflurane, etc.). Both practices should be used in accordance with the Animal Welfare Act to ensure that pain and distress are minimized (7 U.S.C. § 2143 (a)(3)(A) (2022)). Treatment of pain should be tailored to the individual animal while taking the following factors into consideration: appropriate drug selection, dosage, procedure, degree of pain, patient health status, etc.

This section highlights some current analgesia and anesthesia best practices that can be referenced by individuals working with animals used for research, testing, education, and exhibition.

** The resources provided are for reference. Please consult with your institution’s veterinarian prior to using analgesics and anesthetics.

Humane endpoints are an important refinement that should be incorporated in animal experiments, especially if animals may experience pain and distress. A humane endpoint is the point at which an animal’s pain and/or distress is terminated, minimized, or reduced using methods such as euthanasia, terminating the painful procedure, relieving the pain with treatment, or restoring a basic requirement (e.g., returning an animal to social housing if isolation causes distress). Some examples of humane endpoints include a certain change in body temperature, body weight, or expression of specific behaviors. When selecting a humane endpoint, consider the various stages of discomfort, and the pain and distress the experiment may cause. An endpoint should be established before it is obvious that the animal will die unless the action is terminated, yet still be compatible with the experiment’s objectives. This promotes animal welfare while also gathering the necessary data from the experiment.