Although studies suggest that inhaling certain scents may reduce stress in humans, aromatherapy is relatively unexplored in veterinary medicine. But new research presented today at the American Physiological Society (APS) annual meeting at Experimental Biology 2017 in Chicago raises the question of whether aromatherapy may be beneficial to horses as well.

Transporting competition horses from one location to another is often disturbing to the animals. The loud noises and confined spaces of a horse trailer and unfamiliar territory of a new venue may cause an increase in heart rate and levels of the stress hormone cortisol. Stress may also provoke unpredictable behaviors such as running and an unwillingness to perform. Stress reduction therapies are highly regulated among competition horses, which often rules out the use of sedatives and herbal treatments.

Albion College student Kylie Heitman observed eight horses across two trips in horse trailers. During each trip, the horses were individually hauled for 15 minutes. In one trial, the animals were exposed to an air diffusion of lavender oil during transport.

In the other, the horses received a diffusion of distilled water. Heitman measured heart rate and blood cortisol levels before and after each animal's hauling. She found that cortisol levels were significantly lower when the horses were exposed to lavender. She also found a small, yet not statistically significant, decrease in the post-transport heart rate when the horses were exposed to lavender. The horses' heart rate increased slightly after spending time in the trailer without aromatherapy. These results warrant more study into lavender as another means for stress reduction in competition horses.