A Preliminary Assessment of Equine Affect in Equine-Assisted Services

Abstract

ABSTRACT Equine-Assisted Services (EAS) involve health services and adaptive recreation that include equine interactions to promote human wellbeing. While research around the human health outcomes of EAS has grown considerably, there has been limited exploration into the impact of such services on a key service provider, the horse. This study evaluated whether there is variation in how EAS horses experience different types of unmounted interactions with humans. To answer this question, we utilized a mixed method, repeated measures experiment in which 56 human participants and 14 horses, working at a 1:1 ratio, completed a series of three interactions common to EAS: a grooming, a leading, and a maze condition. To measure equine affect, we recorded heart rate variability (HRV) continuously, took eye temperature (ET) immediately after each interaction, and recorded horse behavior. A mixed effects model indicated that horses displayed greater sympathetic activation in the grooming condition than the leading via Low Frequency/High Frequency Ratio (LF:HF: p < 0.001; ET: p = 0.003) and maze conditions (LF:HF: p = 0.005; ET: p < 0.001). Horses also showed significantly more stress-associated behaviors, such as elevated head carriage and pawing, in the grooming condition. These results indicate that there is potential for equine stress during a grooming activity; therefore, more research is needed to determine optimal approaches for addressing horse welfare in unmounted EAS activities involving human interaction.