Cortisol and behavioural responses to enrichment in military working dogs

Our objective was to determine the effect of enrichment (exercise coupled with human contact) on cortisol and behavioural responses in 14-kennelled military working dogs to quantify modification induced on these variables and to allow differentiation between two working regimens: a high frequency one (Regular Regimen or RR) and a low frequency one (Irregular Regimen or IR). The RR furnished enrichment every weekday to military dogs; the IR furnished enrichment for one day out of five. The Regimens durations were equivalent per week, for a total of 7 weeks. Our data show that: (1) RR dogs had lower cortisol concentrations than did IR dogs; (2) cortisol concentrations of RR dogs significantly decreased between the first and the last week of observations; this was not the case in IR dogs; (3) all of the studied dogs exhibited stereotypies. Our results suggest that IR dogs undergone an impaired welfare all along the experiment, whereas RR dogs appeared to undergo a period of acute stress at the beginning of their training, resolved over 7 weeks. These differences between working Regimen consequences, considered in the context of literature on dog welfare, and more particularly military dog welfare, suggest an influence of the enrichment frequency