Physiological Indicators of Acute and Chronic Stress in Securely and Insecurely Attached Dogs Undergoing a Strange Situation Procedure (SSP): Preliminary Results

The quality of the attachment bond towards the caregiver may affect the dog’s physiological responses to stressful stimuli. This study aimed to measure chronic and acute physiological parameters of stress in ten securely and ten insecurely attached dogs. The twenty experimental subjects were selected from a sample of dogs that participated with their owners in the Strange Situation Procedure. Saliva samples were collected before (T0) and after (T1) the test. Blood pressure, heart rate, respiratory rate, and rectal temperature were measured after the test, only. At this time, a hair sample was also collected. RM ANOVA was used to analyse cortisol concentrations between secure and insecure dogs at T0 and T1. Mann–Whitney U test or T test were used for other physiological parameters. Insecure dogs had significant higher salivary cortisol concentrations than secure dogs at T1 (p = 0.024), but only a non-significant trend towards higher cortisol concentrations at T0 (p = 0.099). Post-test heart rate also tended to be higher in insecure compared to secure dogs (p = 0.077). No significant differences in hair cortisol concentration were found. The quality of attachment may affect the dog’s physiological response to acute stress, at least when related to separation from the caregiver. The effect of attachment on chronic stress requires further investigation.