Dogs admitted to animal shelters experience psychological stressors resulting in elevated plasma cortisol. We previously found 30 min of human interaction reduced this response. The present study further characterized this effect, with the aim of developing a practical means of reducing stress of shelter dogs. We found that a second day of 30 min of petting reduced cortisol levels as effectively as the first. Further, 15 min of this interaction was as effective as 30 min. During petting, signs of excitation (vocalizations) and anxiety (panting) as well as escaped attempts were reduced, and social solicitation (tail-wagging) increased. However, cortisol levels quickly increased when dogs were returned to the home kennel. Cortisol reductions were pronounced in dogs admitted as strays, but human interaction did not reduce cortisol in a subpopulation relinquished by their owners. We also measured hair cortisol levels to assess stress prior to shelter admittance. Strays and dogs released by their owners showed comparable hair cortisol levels that were intermediate to those of pet dogs living in a home and those of dogs diagnosed with Cushing\u27s disease. The findings show that as little as 15 min of human interaction can moderate cortisol levels of shelter dogs, that the effect is relatively temporary, that source of the dog is an important variable, and that hair cortisol accumulation may be useful to estimate the condition of the dog prior to shelter admittance
