MANIFESTATIONS OF CHRONIC AND ACUTE STRESS IN DOGS

Poor housing conditions, harsh training sessions and uncontrollable or unpredictable social environments are examples of the situations that may lead to reduced welfare status in dogs. Individuals that suffer f rom poor welfare presumably experience stress and may consequently exh ibit stress responses. In order to evaluate stress responses as potent ial indicators of poor welfare in dogs, we review studies dealing with dogs subjected to stressors. The reported stress responses are catego rized as being behavioural, physiological or immunological, and demons trate the various ways stress is manifested in the dog. Stressors such as noise, immobilization, training, novelty, transport or restricted housing conditions have been reported to elicit responses in behaviour al, cardiovascular, endocrine, renal, gastro-intestinal, and haematolo gical parameters. These and other parameters that change during stress may thus be indicative of poor welfare. However, several sources of m isinterpretation have to be considered before stress responses may be used as valid indicators of welfare. Although analogous to the human s ituation, especially chronic stress may impair welfare, most studies d eal with acute stress and do not address chronic stress and related ph enomena. Adaptation may counteract the initial stress response and ren der parameters of acute stress useless for assessing chronic stress. A daptations to stress are thus in themselves indicative of reduced welf are. Such adaptations may be discovered by challenging a stress respon sive system. Additional studies are recommended to investigate acute s tress parameters as possible indicators of chronic stress. Differences in stressor properties and in individual characteristics of dogs intr oduce variability in stress responses. Such variability will complicat e a valid interpretation of stress responses with regard to welfare. O btaining and applying fundamental knowledge of stress responses in dog s and measuring more than one stress parameter are proposed to minimiz e the risk of misinterpreting measurements of stress. (C) 1997 Elsevie r Science B.V.