After the COVID-19 pandemic college campuses faced a mental health crisis within the student population. As such, many college campuses incorporated programs to address student mental health including the use of alternative therapeutic strategies such as equine-assisted interaction. While survey-based research covering collegiate equine-assisted interaction programs is available, tracking of biomarkers during equine interaction is limited. This can be of value due to the physical nature of the therapeutic intervention. Therefore, the objectives of this study were to determine if there is a relationship between the psychological state of the participant, both human and horse, as observed through heart rate measures and perceived participant stress levels. Full-time college students (n = 26) were recruited for an hour long on-campus equine-assisted interaction program that involved ground activities with the horse. Heart rate monitors tracked both the human and horse participants. Perceived pre- and post-stress levels were determined through a survey instrument using a 4-point Likert Scale with a score of 4 reflecting ‘high stress’. Post-heart rates significantly increased in both the human (post-pre difference: 13.8+16.7 bpm) and horse (post-pre difference: 6.4+6.6 bpm) participants (P < 0.001) with a moderate negative correlation observed between human and horse heart rates (r = -0.46), suggesting human-horse physiological coupling during the event. Perceived stress levels significantly dropped post-equine interaction (post-pre difference: -0.7+1.1; P < 0.001) and there was a negative moderate correlation observed between heart rate and stress levels (r = -0.30) within the human participant, although a correlation was not observed between horse heart rate and participant perceived stress levels (r = -0.07). As an exercise-based therapeutic intervention, equine interaction offers a unique strategy for addressing stress within the student. Further, the physiological coupling between humans and horses may offer an additional benefit not observed within other on-campus mental health programs utilizing physical activity.