# War Exposure and Canine Cortisol Responses: Country Differences in Cortisol Profiles of Therapy Dogs

## TL;DR

Therapy dogs in war zones show different stress hormone levels compared to those in peaceful areas, suggesting environment affects their stress more than their work.

## Contribution

First study to compare cortisol profiles of therapy dogs in war and non-war settings.

## Key findings

- Ukrainian therapy dogs had significantly lower urinary cortisol levels compared to German dogs.
- No significant salivary cortisol changes were observed in relation to DAI sessions.
- Environmental conditions appear to influence stress physiology more than participation in DAIs.

## Abstract

Dog-assisted interventions (DAIs) are utilized in numerous settings, including treating post-traumatic stress disorder in military personnel. However, implementation during active warfare and the welfare of the dogs involved have not been measured yet. This study evaluated stress-related hypothalamic–pituitary–adrenal (HPA) axis processes in therapy dogs involved in DAIs in Ukraine and in a control cohort in Germany. Salivary, urine, and hair cortisol concentrations were measured to assess acute and long-term stress. Ukrainian dogs displayed significantly lower urinary cortisol levels compared to German dogs, suggesting altered long-term glucocorticoid secretion associated with environmental stressors related to war. No significant salivary cortisol changes were observed in relation to DAI sessions. These findings indicate that environmental conditions, rather than participation in DAIs, may influence stress physiology in therapy dogs.

Dog-assisted interventions (DAIs) are an established procedure to support military staff, but their implementation during active warfare has not yet been systematically studied. In addition, the welfare of therapy dogs participating in DAIs during war remains unexplored. Therapy dogs may develop clinically relevant emotional disorders, including trauma-related stress responses, analogous to human psychopathologies. The present study sought to monitor physiological arousal in therapy dogs performing DAI sessions with their handlers in two Ukrainian military hospitals (Vinnyzja and Kyiv). Biomarkers of hypothalamic–pituitary–adrenal (HPA) axis activity, including salivary, urinary, and hair cortisol concentrations, were assessed in Ukrainian (UA) therapy dogs to capture their acute and long-term stress responses. Additionally, cortisol levels in German (GE) therapy dogs performing similar DAIs under peaceful conditions were measured to compare cortisol levels between dogs from both regions. Results suggest that GE therapy dogs exhibited significantly higher urinary concentrations, reflecting alterations in longer-term glucocorticoid secretion that is possibly caused by war-related stimulation in the UA cohort. In contrast, no significant differences in salivary cortisol emerged as a consequence of performing DAIs. The present findings suggest that the environment rather than involvement in DAIs has an impact on therapy dogs’ cortisol secretion.