9 - The Effects of Feeding Cannabidiol Oil on Behavior of Stalled Horses

Using cannabidiol (CBD) in animals has increased since the 2018 Agricultural Improvement Act was passed. Previous work in laboratory animals suggests supplementation with CBD reduced anxiety, compulsive behaviors, and brain activity of limbic and paralimbic areas. Horses exhibit anxiety due to training or housing situations, which is sometimes expressed via stereotypic behaviors including cribbing, aggression, etc. These behaviors can indicate underlying stressors and sometimes causes impairment; therefore, supplementing CBD may reduce undesirable behaviors in horses, consequently improving the health and overall welfare. The study objective was to determine if a single oral dose of CBD would result in adverse effects in horses. Four mature mares and four mature geldings were used in a randomized-control treatment design. Horses typically housed in paddocks, but not novel to stalling were housed in 11’ X 14’ stalls with cameras to record behavior, feed, and water intake. Horses were acclimated to feeding methods and stall environment for one week. Behavior was recorded for 24hr after a dosage of olive oil was administered as a control (CON). Horses were returned to their paddock for one week, then randomly assigned to either a LOW (0.3mg/kg BW; n = 4) or HIGH (0.6 mg/kg BW; n = 4) treatment of CBD oil. After oral dosing, horses were stalled for observation. Stereotypic behaviors such as pawing, cribbing, and aggression were quantified using the Observer XTTM program. Observations were analyzed in R Studio© for analysis of variance (ANOVA). The occurrence of stereotypic behaviors was lower (P = 0.03) in horses given oral CBD. Actions occurred more frequently during feeding sessions, behaviors including aggression and pawing occurred less when horses were given the High dose compared to Control (113 to 26 and 69 to 27) respectively. Based on results, oral administration of the particular cannabidiol product used in this study may mediate negative behaviors in stalled horses.