Beyond the Mission: Long-Term Endocrine Dynamics in Search and Rescue Dog–Handler Teams

Search and rescue (SAR) dog-handler teams work under challenging conditions that may influence long-term physiological stress and arousal. Hair steroid analysis provides a reliable measure of chronic endocrine activity in SAR teams. Hair cortisol (HCL) and hair testosterone (HTL) offer non-invasive markers of chronic hypothalamic-pituitary-adrenal (HPA) and (the hypothalamic-pituitary-gonadal) HPG axis activity. This study examined long-term endocrine patterns in SAR dogs and their handlers and explored correlations within and between species. Hair samples were collected from 60 SAR dogs and their handlers. Dog hair was taken from the interscapular region, and human hair from the occipital area. Cortisol and testosterone were extracted using established methanol-based protocols and quantified via ELISA. Dogs showed a mean HCL of 10.974 pg/mg and a mean HTL of 3.008 pg/mg. Female dogs had significantly higher cortisol levels than males, and cortisol tended to increase with age. Testosterone did not differ by sex, breed, or castration status. Handlers showed a mean HCL of 10.874 pg/mg and a mean HTL of 2.925 pg/mg, with no sex differences. However, handler cortisol levels varied significantly by dog breed. Additionally, HCL levels of dogs and their handlers were negatively correlated.