Animal well-being. IV. Specific assessment criteria

A number of factors have potential use as indicators of animal well-being. Classic and practical criteria for assessing animal well-being are a combination of general health status, clinical signs of disease, and performance. Numerous regulatory mechanisms and systems are responsible for many neurochemical and endocrine changes in response to arousing and stimulating events. Neuroendocrine changes associated with aversive stimuli have been implicated in modulation of immune responses. Animal behavior and preference, which can be observed directly and noninvasively, can be useful in assessment of well-being. Aversive conditions, especially longer term, can cause morphologic and pathologic changes in some tissues.