Cortisol levels in the blood of dogs with different temperament characteristics under the action of a stress factor

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The aim of this study was to determine the characteristics of the hormonal stress response in dogs with different temperament traits by analyzing the dynamics of plasma cortisol levels under the influence of an acute acoustic stressor. The study was conducted on 30 clinically healthy male German Shepherd dogs aged 3.9±0.2 years. Temperament traits (aggressiveness, fear and anxiety, excitability, trainability, and obedience) were assessed using the standardized C-BARQ methodology. Acute stress was induced using the open field test combined with an acoustic stimulus (thunder sound, 90–100 dB). Plasma cortisol levels were measured before exposure to the stressor and at 15, 30, and 60 minutes after exposure using an enzyme-linked immunosorbent assay. The results demonstrated that both the intensity and duration of the hormonal stress response significantly depended on temperament characteristics. In the acute phase of the stress response (15 minutes), aggressiveness had the greatest influence on cortisol levels, whereas fear and anxiety predominated during the recovery phase. Excitability was a key determinant of basal cortisol levels, while low trainability and obedience were associated with prolonged elevation of cortisol following stress exposure. Dogs with calm behavior exhibited lower peak cortisol concentrations and faster restoration of hormonal balance, whereas animals with pronounced behavioral disturbances showed high and sustained endocrine responses. The obtained results confirm the key role of temperament in shaping individual stress reactivity in dogs and have practical significance for assessing adaptive capacity, optimizing housing conditions, training strategies, and veterinary management.