Many people employ aromatherapy as a natural stress reliever, but could the same approach be used to calm stressed or nervous horses? According to study results from one research team, aromatherapy might have a place in the barn, after all.

Clarence E. Ferguson, PhD, an associate professor in the Department of Agricultural Sciences at McNeese State University, in Lake Charles, La., and colleagues recently tested lavender aromatherapy’s efficacy at decreasing horses’ heart and respiratory rates after a stressful experience.

Ferguson’s team recorded seven mature Quarter Horses’ heart and respiration rates while the animals were at rest in their stalls. They assigned each horse a "calm score," which ranged from 1 to 5 (1 being very calm and 5 being very excited) and was based on "the level of calmness observed as several people walked in and out of the stall." The researchers separated the horses into two groups; one group acted as a treatment group and the other as controls. After about one week, the researchers subjected the groups to the opposite treatment.

Researchers placed horses in both groups in individual stalls before sounding an air horn adjacent to the stall twice. Following that stressful experience, the team measured horses’ heart and respiration rates (stressed rates) for one minute.

Next, the team exposed horses to humidified air for 15 minutes—the treatment horses received air produced from a mixture of water and lavender essential oil while the control horses only received water—before remeasuring the horses’ heart and respiration rates (recovery rates).