Welfare considerations: Salivary cortisol concentrations on frequency of therapy dog visits in an outpatient hospital setting: A pilot study

The animal-assisted therapy field is exponentially growing under the lack of science-based evidence of potential risks to the animals involved. Even though to become a therapy dog, the dog must pass an evaluation, most evaluations do not take into account disposition. Thus, a dog could become certified as a therapy dog but still become uncomfortable in stressful situations. Therefore, it is important to understand the magnitude of stress therapy dogs may experience during visits and if the amount of visits per month affects the level of stress. In this 4 × 4 Latin square-designed pilot study, four therapy dog teams were randomly assigned to an outpatient nursing unit at Mayo Clinic, Rochester, MN. The therapy dog teams were then randomly assigned to the order of the four treatments. The treatments include: treatment A, two visits a week over the course of four weeks; treatment B, one visit a week over the course of four weeks; treatment C, two visits over the course of four weeks; treatment D, one visit over the course of four weeks. Interestingly, this study noted a dog × time effect. Dog 3, the youngest in the study, had the highest postsalivary cortisol for treatment A, C, and D. When comparing pre and postsalivary cortisol concentrations, only treatment A was significantly different (P = 0.04). This novel study was the first to assess the frequency of therapy dog visits’ effect on therapy dog salivary cortisol. In comparing baseline to postvisit salivary cortisol concentration, treatment A had a significant reduction in cortisol postvisit. These data suggest that the more frequently, two visits a week, the therapy dog visits, the lower the cortisol concentrations will be. To further evaluate the welfare and potential state of stress in therapy dogs, researchers need to collect additional biological, objective parameters and have visits uniformed and recorded for behavioral analysis.