Attachment patterns toward the caregiver modulate canine physiological indicators of acute and chronic stress

Attachment bonds are central to emotional regulation in humans, yet their impact on stress physiology in interspecific relationships remains scarcely explored. In human infants, insecure attachment is linked to heightened short- and long-term stress responses. Here, we extend this framework to dogs, a species sharing close social bonds with humans, to investigate whether attachment behavior patterns, as assessed during the Strange Situation Procedure (SSP), influence dog stress physiology. Our findings suggest that anxious attachment in dogs was associated with stronger acute stress responses, as reflected by elevated heart rate, rectal temperature, and salivary cortisol concentrations. In contrast, dogs displaying greater willingness to maintain contact with their caregiver exhibited lower heart rate and reduced hair cortisol concentrations, suggesting a protective effect of secure attachment against chronic stress. Our findings indicate that the quality of dogs' attachment to the human caregiver may modulate their physiological response to stress, in both the short- and long-term.