Latham 2004). Overall, however, the presence of stereotypies should be a cause for concern because animals that exhibit such behavioral patterns may not only have experienced some stress or distress in the past but also live in environments that promote or sustain these abnormal behaviors. Moreover, as a study by Krohn and colleagues has shown, stereotypies are probably underreported as they may occur during the night when staff are not present, or cease when staff enter a room (Krohn et al. 1999). If, in fact, the presence of stereotypies is being investigated, then more sophisticated methods such as closed-circuit television or videorecording, or simpler diagnostics such as partially reversed light cycles, would enable staff to observe nocturnal animals during their most active periods in order to document instances of abnormal behavior (Hubrecht 1997).
Recognition of distress should be derived from intimate knowledge of the species’ or strain’s normal behavior and may be based on (1) clinical signs and/or (2) significant deviation from the expected behavioral repertoire. Some clinical signs (e.g., changes in temperature, respiration, feeding behavior) indicate an abrupt onset of distress while others (e.g., weight loss) develop over a longer period of time and may serve as warnings. A thorough clinical examination with references to baseline effects of age, gender, genotype, etc., is necessary to establish the presence of distress, while an abrupt and marked change in behavior lasting more than a few days may also indicate a disease state. While the presence of stereotypies is undesirable, the relationship between stereotypic behavior and distress remains largely unknown. Preventing the development of stereotyped behavior by providing species-specific appropriate environments is likely to result in improved welfare.
Assuming that an animal’s behavior has been well characterized, indications of distress may include certain clinical signs or marked change from the individual animal’s usual behavioral repertoire (Morton and Griffiths 1985; see score sheet examples in Appendix). An abrupt and marked change in behavior lasting more than a few days may also indicate the presence of a disease state in addition to distress, particularly if these changes occur in conjunction with severe reductions in normal daily activities such as feeding behavior, sexual behavior, maternal behavior, or attention to threat. Conversely, animals may exhibit increased activity associated with unusual motions (e.g., head rubbing) or unusually high levels of certain behaviors (e.g., scratching). Even marked changes in behavior, however, must be evaluated in context. For example, females usually exhibit decreased activity the first day following parturition, an expected behavior.