Methods for evaluation of laboratory animal well-being.

Well-being is a relative concept, referring to the state of an animal in relation to its ability to cope with its environment. This ability to cope is what we usually try to measure when evaluating the animal's well-being. Good welfare is, in general, considered to be related to a broad behavioural repertoire, which requires a considerable knowledge of the animal's species-specific behaviour and their basic biology. Ideally, well-being should be measured in a positive way, such as measuring pleasure by anticipatory behaviour. However, parameters have more often been designed for detecting failures to cope, leading to stress and/or discomfort. Parameters used in the assessment of discomfort are behavioural parameters, such as stereotypies, reduction in grooming, changes in activity; physiological parameters, such as body weight, abnormal posture, respiratory signs, heart rate, hormone levels; and post-mortem signs, as retrospective parameters, such as stomach ulcers, adrenal cortex size, fatty deposits. The usefulness of these parameters is discussed.