phaidra.vetmeduni.ac.at o:4082 DOI 10.1016/j.ctcp.2025.101937 Heart rate and salivary cortisol as indicators of arousal and synchrony in clients, therapy horses and therapist in equine-assisted therapy This exploratory study aimed to analyse physiological interaction processes in equine-assisted-therapy (EAT) between client, therapy horse and therapist.We measured heart rate (HR), heart rate variability (HRV) and cortisol levels before, during and after a standardized therapy session and a control condition in one therapist, four therapy horses and ten female clients in emerging adulthood (Mn = 21.8 years, SD = 3.39). The clients were diagnosed with mild (N = 5) to moderate (N = 5) intellectual disability (ID).There was no significant change in the client's HR, HRV and cortisol levels during an EAT session. No difference was observed between therapy sessions with or without a therapy horse, except during the challenge phase of the EAT protocol, where clients had a significantly lower HR when interacting with the therapy horse. HR between therapist and client correlated significantly, as well as between therapist and horse. This effect was greater when therapists interacted with a familiar horse. Clients' and horses' HRs also correlated, but only when the horse was the clients' familiar and preferred horse.These results indicate that relationship intensity is an important factor for the synchronization process. Moreover, the inclusion of horses in a therapeutic setting can lead to a decreased HR in young adults with intellectual disability while mastering a challenge. Future research should investigate this potential benefit of EAT, considering the reciprocal influences and the relationship between client, therapist and horse. eng Female Hydrocortisone Analysis Hydrocortisone Metabolism Equine-Assisted Therapy Methods Humans Animals Heart Rate Physiology Horses Saliva Chemistry Young Adult Adult Arousal Physiology Intellectual Disability Therapy Male 2025-04-28T09:32:52.931Z LOMv1.0 Author BEGIN:VCARD VERSION:3.0 N:Naber;Anna; FN:Anna Naber END:VCARD BEGIN:VCARD VERSION:3.0 N:Kreuzer;L.; FN:L. Kreuzer END:VCARD BEGIN:VCARD VERSION:3.0 N:Zink;Roswitha; FN:Roswitha Zink END:VCARD BEGIN:VCARD VERSION:3.0 N:Millesi;Eva; FN:Eva Millesi END:VCARD BEGIN:VCARD VERSION:3.0 N:Palme;Rupert; FN:Rupert Palme X-ORCID:https://orcid.org/0000-0001-9466-3662 END:VCARD BEGIN:VCARD VERSION:3.0 N:Hediger;Karin; FN:Karin Hediger END:VCARD BEGIN:VCARD VERSION:3.0 N:Glenk;Lisa; FN:Lisa Glenk X-ORCID:https://orcid.org/0000-0002-5814-0546 END:VCARD https://w3id.org/kim/hcrt/scheme https://w3id.org/kim/hcrt/text Textdokument Text LOMv1.0 yes https://creativecommons.org/licenses/by-nc-nd/4.0 application/pdf 2720530 https://phaidra.vetmeduni.ac.at/o:4082 https://phaidra.vetmeduni.ac.at/api/object/o:4082/thumbnail LOMv1.0 discipline