The study aims to determine the impact of canine-human relationships on dogs’ susceptibility to stress during tests that evaluate a dog’s suitability for canine-assisted therapy. Twenty-four dogs and their owners were included in the study. Dogs from all groups were most likely to manifest stress by nervous tail wagging/hugging, which could suggest that tail movements and the position of the tail are the key markers of emotional states in dogs. An analysis of pooled results revealed that dog-owner relationships influenced the animals’ susceptibility to stress. These findings indicate that human-canine bonding plays an important role in dog behaviors. In this study, stress levels were higher in dogs that were less bonded with their owners. Apparently, dogs that have good contact with humans are better equipped to cope with stress than animals which are less reliant on their owners.