The Use of Equine Lavender Aromatherapy to Suppress Stress
Authors: Heitman Kylie Renee , Rabquer Bradley James 
Published: November 2023

Interrupting horses from their typical day‐to‐day routines has the potential to cause horses to develop unnecessary stress. Competition horses encounter a wide variety of unnatural and stressful stimuli through hauling to new venues, loud noises, and limited turnout. Unfortunately, many drug regulations are in place for sedatives, tranquilizers, herbs, and other therapeutic tools for those competition horses, creating a challenging decision when it comes to finding useful stress‐reducing tools. Lavender has the potential to be used as a therapy in equines to reduce stress levels. When used as an aromatherapy in competition horses, it is a potential alternative that is not illegal.The objective of this study was to determine whether lavender, when diffused into the air, could be used to decrease heart rate and blood cortisol levels in horses encountering stressful situations like hauling horses in a horse trailer. The specific aim of this study was to determine if cortisol levels and heart rate (HR) levels were suppressed when essential lavender oil is administered through the air during a stressful stimulation. While other studies have explored the benefits of essential oils in human and dog models, it is a relatively unexplored area in equine physiology and veterinary medicine.A total of fourteen horses were individually hauled in a trailer for 15 minutes. Seven of the horses served as the treatment receiving the lavender aromatherapy treatment, and seven horses served as the control receiving distilled water aromatherapy. At baseline in the control group, we measured, in beats per minute (bpm), an average HR of 34.3 bpm (+/− 3.5 S.D), which was elevated to 42.4 bpm (+/−3.3 S.D) immediately after stimuli. At baseline in the treatment group, we measured an average HR of 33 bpm (+/−3.2 S.D), which was elevated to 37.8 bpm (+/− 4.9 S.D) immediately after stimuli. Despite the decrease, there was no significant difference in HR between the control and treatment groups after stimuli (p‐value 0.0714). In addition to HR, we also assessed blood cortisol levels. The baseline cortisol in the control group was 2,166 pg/ul (+/− 1,964 S.D), which was elevated to 11,528 pg/ul (+/− 3,535 S.D) after stimuli. At baseline in the treatment group, the cortisol levels were 340 pg/ul (+/− 218 S.D), which was elevated to 6,815 pg/ul (+/− 4,118 S.D) after stimuli. There was a significant difference between the control and treatment groups at the baseline (p‐value 0.0453) and after stimuli (p‐value 0.0481) cortisol measurement.Stimulation by hauling the animals resulted in an increase in HR and treatment with lavender aromatherapy resulted in a nonsignificant decrease in HR. However, the cortisol data was unreliable due to the significant difference in the baseline cortisol levels between the control and treatment groups.Support or Funding InformationThis work was supported by the Albion College Biology Department, the Foundation for Undergraduate Research, Scholarship, and Creative Activity (FURSCA), and the Hewlett‐Mellon Fund for Faculty Development at Albion College.