Humane Endpoints for Infectious Disease Animal Models

The obligation to minimize or eliminate unnecessary pain and distress animals may experience when they are used in biomedical research, teaching, and testing is clearly stated in the Canadian Council on Animal Care guidelines on choosing an appropriate endpoint in experiments using animals for research, teaching, and testing: "In experiments involving animals, any actual or potential pain, distress, or discomfort should be minimized or alleviated by choosing the earliest endpoint that is compatible with the scientific objectives of the research. Selection of this endpoint should involve consultation with the laboratory animal veterinarian and the animal care committee" (CCAC 1998, p. 2). Additional guidance is provided for animals used in infectious disease studies, as follows: "For all infectious disease research, including virulence tests in animal models, endpoints should be established that minimize the potential for pain and/or distress in the animals" (CCAC 1998, p. 15). Since the work of pioneers such as Jenner and Pasteur (Fenner et al. 1997) more than a century ago, animal models have provided essential information in the study of infectious diseases. Although much experimentation can now be accomplished with in vitro systems, animals continue to be necessary for this field for studying the process of inflammation, specific infectious diseases, and pharmacologic treatment of infectious diseases; vaccine development and efficacy and safety testing; virulence testing; and, for diagnostic purposes, in both human and veterinary medicine. The use of whole animal models, both natural and induced (including transgenic models), is considered important to the understanding of the very complex temporal relationships that occur in infectious disease involving the body, its neuroendocrine and immune systems, and the infectious organism.