the American Veterinary Medical Association in 1993 when the American College of Veterinary Behaviorists (ACVB) was given specialty-board status.
In the research environment, routine behavioral observations can aid in the detection of disease in animals that are not exhibiting any other clinical signs. For example, a cynomolgus monkey was diagnosed with diabetes mellitus through initial observations of uriposia (urine-drinking) (Levanduski et al., 1992); the tentative diagnosis was then confirmed with urinalysis and blood-chemistry evaluation. Sensitive indicators of animal health include measures of food or fluid intake and performance of specific tasks (NIH, 2002).
Because of the long-term use of individual animals in a neuroscience or behavioral study, the physical proximity between researcher and animal, and the wide variety of behavioral data collected during a study, neuroscientists have an excellent opportunity to monitor animal behavior and health. Subtle changes detected in the animal’s demeanor or its willingness to work in a study or sudden changes in performance on behavioral tasks may be the first indicators of a health problem that should be investigated. If such changes are noted, the researcher should promptly notify the veterinarian so that the animal can be more fully evaluated.
Endpoints are established for both experimental and humane reasons. An experimental endpoint is chosen to mark the planned end of an experimental manipulation and associated data gathering. A contingent experimental endpoint may also be used to signal euthanasia to remove an animal from the study for humane reasons. On the other hand, in experiments with unrelieved or unanticipated pain/or distress, humane endpoints are criteria that indicate or predict pain, distress, or death and are used as signals to end a study early to avoid or terminate pain and/or distress. Ideal endpoints are those that can be used to end a study before the onset of pain and/or distress, without jeopardizing the study’s objectives. However, in most cases, humane endpoints are developed and used to reduce the severity and duration of pain and/or distress (Stokes, 2000).
Humane endpoints should reflect actual or imminent deterioration of an animal’s condition, and they should be easy to assess over the course of the study (Toth, 2000). General categories of endpoints include biologic markers, such as the development of paralysis in models of neural tumors (Huang et al., 1993, 1995); markers of therapeutic failure, such as persistent signs of tumor growth despite drug intervention; markers of disability, such as inability to stand in models of bacterial endotoxemia (Krarup et al., 1999); markers of disease exacerbation, such as increased seizure frequency; and general markers of clinical deterioration, such as substantial changes in body weight, alertness, respiration, and body temperature (Redgate et al., 1991; Toth, 1997).