Suttkus, S.; Schumann, A.; Gupta, Y.; de la Cruz, F.; Geisler, M.; Rieger, K.; Schulz, S.; Ganser, G.; Bär, K.-J.

Introduction: Canine-assisted psychotherapy (CAP) introduces a therapy dog into the therapist-patient relationship and may influence interpersonal processes underlying therapeutic change. This exploratory pilot study investigated whether direct patient-dog contact is associated with changes in autonomic arousal and therapist-patient physiological synchrony. Methods: Skin conductance was recorded from 18 patients with depressive disorders and one therapist during 53 routine CAP sessions. A total of 192 episodes of direct patient-dog contact were identified from video recordings. Three-minute periods before and after each contact onsets were compared. Skin conductance level (SCL), skin conductance fluctuations (SCF), and therapist-patient physiological synchrony were assessed using zero-lag correlation and maximum cross-correlation. Sliding-window analyses examined temporal changes in synchrony, while randomly selected pseudo-events served as controls. Results: SCL increased significantly following dog contact in both patients and the therapist, whereas SCF rate over 3 min did not change significantly. Therapist-patient physiological synchrony increased significantly after dog contact, as indicated by both zero-lag correlation and maximum cross-correlation. Sliding-window analyses confirmed these increases and showed a reduction in the temporal lag between the two physiological signals. Importantly, increases in synchrony were significantly greater following genuine dog-contact events than following pseudo-events. Discussion: Direct physical contact between patients and therapy dogs is followed by increased autonomic arousal and enhanced therapist-patient physiological synchrony. These findings suggest that dog-patient contact may function as an interactional event that promotes physiological coordination and interpersonal attunement within the therapeutic dyad.