A Successful Case of Measuring Horse Welfare during Equine-Assisted Interactions with Military Veterans with PTSD

Although it is known that equine-assisted interventions (EAI) have beneficial effects on human participants, the effects on horses have not been extensively studied. This study investigated the effects of EAI with military veterans with post-traumatic stress disorder (PTSD), on the heart rate (HR), heart rate variability (HRV), and behaviour of the involved horses. In total six different horses were deployed multiple times during a 12-week program of EAI for veterans with PTSD. The HR and HRV were measured during baseline conditions, free activities and directed activities. The free activities consisted of social interactions and relaxation. The directed activities consisted of shared activities with the horse such as grooming, groundwork and riding. We investigated whether the different types of activities affected HR and HRV. In addition, we investigated whether there were behavioural changes throughout weeks 1, 6 and 12 of the program that indicated welfare effects. Baseline conditions and free activities did not significantly differ in HR and HRV, but during the directed activities HR was significantly higher and HRV significantly lower due to the difference in activity level. These results indicate that the type of activity during EAI affects HR and HRV measurements and that this should be considered when studying the effects of EAI on horse welfare. This study shows that non-invasive measurements of horse welfare are practically feasible during EAI. No negative effects of the activities on horse welfare were found.