Collyer, P. B., Wilson, H. S. 2016. Does a commercial pheromone application reduce separation anxiety in separated horse pairs? Journal of Veterinary Behavior 15, 94. (12th International Society of Equitation Science (ISES) Conference Abstract)

Horses may display increased locomotory and vocal activity when separated from their preferred partners, which can increase anxiety levels and injury risk. This study evaluated physiological and behavioral evidence of separation anxiety in separated preferred partners, and the potential stress-reducing effect of Confidence EQ® (CEVA), a pheromone gel for intranasal application. Four strongly bonded horse pairs of various breeds were familiarized three times with Polar equine belts and the intranasal application of the product or a placebo. A Latin Square research design was used with complete randomization of separation combinations comprising 2 horses × 2 locations × 2 treatments. Baseline recordings of heart rate (HR) and HR variability were undertaken on pasture for one hour prior to separation. Both horses were given either a placebo or treatment thirty minutes before the one-hour separation (stall, pasture, with conspecifics). All sessions were videographed for behavioral analysis. MANOVA with pairwise comparisons was performed on standardized physiological or behavioral variables to test for location and treatment effects. There were no significant differences between treatments within separation locations (Z < 1.26; P > 0.05), or when comparing the physiological disparity between pasture and barn locations (Z = 1.76, P > 0.05). These results suggest that the pheromone does not profoundly reduce separation anxiety, but could potentially have potential for mitigation of the extremeness of anxiety, especially when separation involves relocation of horses to a novel environment. Further research with larger sample sizes for its use in increasing the safety of horse and handler during training of horses is needed.