Authors: Thomson Alexander C S, McCarrel Taralyn M, Zakharov Alexander, Gomez Beatriz, Lyubimov Alex, Schwark Wayne S, Mallicote Martha F, Portela Diego A, Bisiau Amber L, Wakshlag Joseph J
Journal: Frontiers in veterinary science
Summary
# Editorial Summary: Cannabinoid Pharmacokinetics and Safety in Horses Researchers administered a commercial CBD/CBDA-rich hemp oil to eight horses at doses of 2 mg/kg or 8 mg/kg in a randomised cross-over study to characterise how equine bodies absorb, distribute and eliminate cannabinoids, and to establish safety parameters in this species. Using high-performance liquid chromatography with tandem mass spectrometry to track serum concentrations over 48 hours, combined with comprehensive assessment of vital signs, gait, mentation, gastrointestinal transit and blood chemistry, the team found that peak cannabidiol concentrations were dose-dependent (5.2 ng/mL at 2 mg/kg versus 40.35 ng/mL at 8 mg/kg), whilst cannabidiolic acid showed markedly higher bioavailability and biphasic absorption kinetics, peaking at 36.95 and 353.56 ng/mL respectively. The elimination half-life for CBD could only be calculated at the higher dose (7.75 hours), suggesting rapid clearance at lower doses, and no adverse effects on neurological function, behaviour or gastrointestinal health were detected at either dose. These findings provide critical baseline pharmacokinetic data to support evidence-based dosing protocols for hemp-derived cannabinoid products in equine practice, whilst demonstrating that single-dose administration is well-tolerated—though practitioners should note that CBDA's superior absorption and biphasic profile may differ substantially from the kinetics of isolated CBD products.
Read the full abstract on PubMed
Practical Takeaways
- •Commercial CBD hemp oil products in horses show rapid clearance and low bioavailability at lower doses, suggesting variable clinical efficacy may relate to absorption inconsistency rather than toxicity concerns
- •Single doses up to 8 mg/kg appear safe for use in horses with no observable neurologic or gait changes, supporting short-term tolerability for trial use in clinical settings
- •The biphasic absorption of CBDA and dose-dependent pharmacokinetic differences suggest that product formulation and dosing strategy significantly influence plasma cannabinoid levels and may affect therapeutic outcomes
Key Findings
- •CBD peak plasma concentration was 5.2 ng/mL at 2 mg/kg dose and 40.35 ng/mL at 8 mg/kg dose, with CBDA showing higher peak levels (36.95 and 353.56 ng/mL respectively)
- •Elimination half-life of CBD was 7.75 hours in the 8 mg/kg group but could not be calculated for the 2 mg/kg group due to rapid clearance below quantifiable limits
- •Single-dose enteral CBD/CBDA administration up to 8 mg/kg produced no significant differences in neurologic, behavioral, gastrointestinal, or vital parameters compared to control
- •CBDA showed biphasic absorption kinetics, indicating complex bioavailability patterns distinct from CBD