Utilization and Care of Vertebrate Animals Used in Testing, Research, and Training, “Proper use of animals, including the avoidance or minimization of discomfort, distress, and pain when consistent with sound scientific practices, is imperative. Unless the contrary is established, investigators should consider that procedures that cause pain or distress in human beings may cause pain or distress in other animals” (IRAC 1985). Similarly, the federal Animal Welfare Act Regulations (USDA 2005), the Guide for the Care and Use of Laboratory Animals (NRC 1996), U.S. Public Health Service Policy for the Humane Care and Use of Animals (DHHS 2002), and policies of the Association for Assessment and Accreditation for Laboratory Animal Care International (AAALAC International) all require the identification, minimization, and elimination of sources of pain and distress in laboratory animals, consistent with the goals of the research.
These policies address pain and distress jointly as both are considered unpleasant and potentially harmful to the animal subjects. From a scientific perspective, however, pain and distress are quite different and should be examined separately so that each receives appropriate emphasis. This is especially true for distress, as it has been difficult to define and there is relatively little research in this area. In fact, only a small portion of the 1992 report discussed distress because at that time very little scientific information was available. While more information was available for this report, it is still difficult to pinpoint exact measures of distress.
Due to the paucity of information and the lack of a clear, widely accepted definition for distress, the biomedical research community, including investigators, veterinarians, animal care staff, and IACUCs, has not had reliable guidance in recognizing, assessing, or alleviating distress. Because regulations call for the minimization or elimination of distress, it is imperative to attempt an evaluation of the state of the science and to translate current scientific knowledge into practical guidelines for use in laboratory animal facilities. Specifically, the Committee was tasked with preparing
a report on stress and distress [that] will review the current scientific literature regarding mechanisms of stress and distress for animal models used in biomedical research as well as the literature regarding methods for recognizing and alleviating distress. Emphasis will be placed on: the scientific understanding of causes and functions of stress and distress; determining when stress becomes distress; and identifying principles for recognition and alleviation of distress. Specific emphasis will be placed on the identification of humane endpoints in situations of distress and principles for minimizing distress in laboratory animals…. [G]eneral guidelines and examples will be given to aid IACUC members, investigators and animal care staff in making decisions about protocols using laboratory animals under current federal regulations and policies. Recommendations will be