Effects of three non-confrontational handling techniques on the behavior of horses during a simulated mildly aversive veterinary procedure

In a randomized between-subjects design, we evaluated the effectiveness of each of three non-confrontational handling interventions compared to no intervention control on the behavior of horses during a single-trial simulated mildly aversive health care scenario. These handling interventions included withers scratching (WITHERS, n = 12), face and eye rubbing (EYES, n = 12), and feeding (FEED, n = 12) for comparison with no intervention control (CON, n = 12). The simulated health care scenario included confinement in a novel clinical environment away from pasture mates, along with a 3-min exposure to a mildly aversive auditory stimulus (electric sheep shears hand held at a standard 3 m from the horse, 85 dB at ear level of horse). Sessions were video recorded for subsequent detailed quantitative evaluation of avoidance/stress behavior responses during the 3-min auditory stimulus. Additionally, heart rate was telemetrically recorded at 5-s intervals during the 3-min auditory stimulus. Mean (+/− SE) avoidance/stress response frequency was 13.7 (3.2) for FEED, 26.9 (2.7) for EYES, 30.4 (5.2) for WITHERS, and 44.2 (5.3) for CON. FEED, EYES and WITHERS each differed significantly from CON (P < 0.05). Mean (+/−SE) average and ending heart rates, respectively, were: 73.7 (4.8) and 68.8 (5.7) for EYES, 75.3 (5.4) and 71.7 (5.9) for FEED, 84.7 (9.2) and 80.3 (10.2) for CON, 92.5 (8.1) and 80.8 (10.1) for WITHERS. For both average and ending heart rate, differences from control were not significant. We conclude that compared to no intervention, each of the three handling interventions was effective in reducing avoidance/stress responses compared in this model. These results provide evidence for recommending non-confrontational handling methods to increase the comfort of horses, as well as improve safety for horses and handlers, during mildly aversive health care procedures.