Psycho-emotional state of dogs with different temperament characteristics under the influence of an acoustic stimulus

This study aimed to assess the psycho-emotional state of German Shepherd dogs with different temperament characteristics under acute stress and anxiety conditions. A modified five-point FAS-M (Fear, Anxiety, Stress) scale, adapted from the original eight-point system (Gatehouse et al., 2025), was applied. The experiment was conducted on 30 male dogs aged 3.9 ± 0.2 years, tested under open-field conditions for five consecutive days. On days 2–3, acute stress was induced by an acoustic stimulus (thunder, 90–100 dB), whereas on days 1, 4, and 5, the anxiety state was evaluated without stimulus exposure. Temperament traits were assessed using the C-BARQ questionnaire, allowing the classification of dogs by aggression, fear and anxiety, excitability, trainability, and obedience. It was established that acute stress caused a significant increase in psycho-emotional scores compared with baseline levels (p < 0.001), with the most pronounced reaction observed on the second experimental day. On non-stress days, gradual score reduction indicated adaptation to the testing environment. Highly aggressive and overexcitable dogs exhibited the strongest reactions to the stressor (up to 3.45 a. u.), whereas obedient and calm dogs showed the lowest reactivity and the fastest behavioral stabilization. Correlation analysis revealed a strong positive relationship between excitability and psycho-emotional state (r = 0.80; p < 0.001) and between aggression and excitability (r = 0.68; p < 0.001). Conversely, trainability and obedience were significantly negatively correlated with psycho-emotional state (r = –0.65; p < 0.001), confirming their protective role against stress development. These findings indicate that individual temperament traits determine the level of stress resistance in dogs and can be used to predict behavioral reactivity in veterinary practice, training, and animal welfare assessment