Expert Report

Recognition and Alleviation of Pain in Laboratory Animals (2009)

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Minimizing and alleviating pain in laboratory animals without compromising the methodological integrity of a research project is important both ethically and legally. Fortunately, recent scientific progress has expanded the understanding of pain and increased the ability to prevent and alleviate it in laboratory animals. This report, developed by a committee convened by the National Research Council at the request of the New Jersey Association for Biomedical Research and the U.S. Department of Agriculture, updates 1992 Research Council guidelines for those involved in the care and use of animals in the research environment. It is intended to help scientists, veterinarians, research administrators, Institutional Animal Care And Use Committee (IACUC) members, and animal care staff to understand the basis of animal pain, recognize and evaluate its presence and severity, and appreciate the means by which pain can be minimized or abolished.

Key Messages

  • Adoption of humane endpoints is critical, particularly in those studies where significant pain is anticipated.
  • Current scientific evidence strongly suggests that mammals, including rodents (which are the most commonly used laboratory animals), are able to experience pain.
  • Pain in animals is difficult to access, mostly due to lack of methods that can validate and objectively measure it.
  • Pain may not only be caused as part of a research procedure, but also may be a by-product of husbandry or other unrelated factors (e.g., aging). Pain may arise not only in response to a noxious stimulus, but also in situations where increased sensitivity to pain is observed (i.e., hyperlgesia), such as following injury and inflammation.
  • The Committee stresses the importance of the Three Rs (replacement, refinement, and reduction) as the standard for identifying, modifying, minimizing and avoiding most causes of pain in laboratory animals.