CBD in horses: evidence and doping
CBD in horses: evidence, doping and safety — independent overview for horse owners and vets.
Short & honest
CBD is barely studied in horses and available evidence is weak. For competition horses, an absolute doping ban applies under FEI and USEF rules.
Safety assessment: Risky
Veterinary review not yet completed
This page is awaiting review by a registered veterinary surgeon. Until then, treat the text as education based on the sources listed — not as a verified veterinary judgement.
What is CBD?
Cannabidiol (CBD) is a non-psychoactive cannabinoid derived from the hemp plant (Cannabis sativa). It binds to the endocannabinoid system, which is also present in horses. CBD is commercially offered as oil, paste or supplement and claimed to help with anxiety, pain, inflammation and muscle tension in horses.
Claims versus evidence
Most claims are based on human research or anecdotes. Veterinary research in horses is scarce and of limited quality.
Behaviour and stress
A controlled study in six horses receiving CBD paste for 15 days found no statistically significant effect on behaviour, heart rate or cortisol levels compared with placebo [2]. The sample was too small for definitive conclusions, but the absence of any signal is notable.
Pain in osteoarthritis
One small RCT (n=12 per group) reported improved pain scores in horses with osteoarthritis receiving CBD as an adjunct to phenylbutazone [3]. The CBD dose used was extremely low and it is unclear to what extent the effect is attributable to CBD. The evidence is preliminary and does not justify routine application.
Pharmacokinetics: long presence in the body
CBD is cleared slowly in horses. The half-life in serum averages 161 hours after multiple doses [1]. In a study in Connemara ponies, the primary metabolite 7-COOH-CBD was still detectable up to 16 days after the last dose [4]. This is clinically relevant for doping control (see below).
Product reliability
An evaluation study of commercial CBD supplements for horses showed that the products contained only 9–13% of the amount stated on the label [5]. This makes dosing practically uncontrollable and comparison between studies difficult.
Doping: a strict prohibition
CBD and CBDA are on the FEI 2026 Prohibited Substances List and are prohibited under USEF regulations. A positive test leads to disqualification, regardless of the reason for use.
| Aspect | Detail |
|---|---|
| FEI classification | Specified substance (accidental exposure possible as a defence, but no exemption for intentional use) |
| Detection window | Up to at least 16 days after last dose [4] |
| Threshold values | Not established — no validated therapeutic dose available |
| Risk | High with any competitive use |
As no official threshold values have been established, no safe withdrawal period can be calculated for competition horses. Use in competition horses is therefore irresponsible.
Safety
Specific toxicity data in horses are largely lacking. In other animal species, liver stress and sedation are known risks at high doses. The combination with other medicinal products — particularly analgesics, sedatives and anti-epileptics — has not been systematically investigated in horses.
Conclusion for practice
CBD in horses is insufficiently researched to make recommendations on efficacy or dosing. For competition horses, use is excluded due to the doping risk and the long detection period. In leisure horses, caution is advised until more and better research is available. Always consult a veterinary surgeon before considering a supplement.
Why this verdict?
Evidence is limited to a few small studies (n=6–12) with methodological limitations: no statistically significant behavioural effect in a controlled study [2], and only one small RCT in osteoarthritis using an extremely low CBD dose as an adjunct to existing pain relief [3]. Pharmacokinetic data are available but clinical efficacy is insufficiently demonstrated for any indication.
Interactions with medication
- Sedatives and anaesthetics (possibly additive sedative effect)
- NSAIDs such as phenylbutazone (combination used in one study [3], interaction profile unknown)
- Antiepileptics (CYP enzyme inhibition suggested in other species, not studied in horses)
Legal status (Netherlands)
CBD and CBDA are prohibited for competition horses under the FEI 2026 Prohibited Substances List and USEF regulations. No safe withdrawal period has been established; detection is possible for at least 16 days after the last dose [4]. For leisure horses, no statutory usage bans apply in the Netherlands, but CBD animal supplements fall outside regular veterinary medicinal product legislation.
Sources
- [1] Pharmacokinetic modelling of orally administered cannabidiol and implications for medication control in horses. Frontiers in Veterinary Science, 2023. Pharmacokinetics doi:10.3389/fvets.2023.1234551
- [2] Behavioral observations, heart rate and cortisol monitoring in horses following multiple oral administrations of a cannabidiol containing paste (part 2/2). Frontiers in Veterinary Science, 2024. Narrative review doi:10.3389/fvets.2023.1305873
- [3] Improved quality of life and pain relief in mature horses with osteoarthritis after oral transmucosal cannabidiol oil administration as part of an analgesic regimen. Frontiers in Veterinary Science, 2024. RCT doi:10.3389/fvets.2024.1341396
- [4] Pharmacokinetics of cannabidiol and its two main phase I metabolites in Connemara ponies. Frontiers in Veterinary Science, 2025. Pharmacokinetics doi:10.3389/fvets.2025.1599934
- [5] Evaluation of an Oral Supplemental Cannabidiol Product for Acceptability and Performance in Mature Horses. Animals (MDPI), 2023. Narrative review doi:10.3390/ani13020245
Questions about this substance for your animal?
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