CBD has been a popular for topic the last number of years. It has been widely used in humans to help with stress, anxiety and even pain relief. Buy what about our horses? Brands such as Equiso and Equisolv come to mind when feeding to horses, but what are the claims?

There have been a limited number of scientific studies completed on CBD, and their effects on behavior’s and health parameters in horses. I have come across many high rating reviews and testimonials for brands but so far, no brand has provided scientific evidence to back up their products claims.

So what does science say?

In a study evaluating CBD in horses, assigned horses into two groups. Horses fed a low dose of CBD (0.3MG/KG of bodyweight) and horses fed a high dose (0.6mg/kg of body weight). For a 500kg horse this is 150mg for low and 300mg for high. The horses were fed one dose of CBD in their feed and evaluated over a 24 hour period. It was found that the HIGH dose treated horses had slightly lower heart rates than the LOW treated horses, but it was still within the normal resting rate(Lockett, 2019).

In another study, investigating the effects of cannabidiol on immune function and health parameters in senior horses, found that horses treated with CBD reduced some inflammatory cytokine production and antibody responses to vaccination (Turner et al., 2023) The horses were fed a daily dose of 2mg/kg of body weight, 1,000mg for a 500kg horse, for a period of 90 days. The horses showed no adverse side effects as measured by the complete blood count or chemistry profiles.

From these studies it can be seen that CBD has an effect on resting heart rates and inflammatory responses in older horses, but what about behavior’s? CBD has been marketed as a horse calmer and aid in stressful situations. In a study investigating the effects of pelleted cannabidiol supplementation on heart rate and reaction scores in horses (Draeger et al., 2021) found that horses fed with 100mg/ day of CBD exhibited less reactivity to a novel stimulus test, compared to the control horses. The heart rates at the start of the stimulus, during and after were recorded and no difference was seen between the treated group and the control group. The treated horses were fed the daily dose of CBD for six weeks prior to the novel test. This is a positive sign that CBD can have an effect on horses reactivity to new stimulus.

In a case study looking at the effect of CBD on long term windsucking (Zamith Cunha et al., 2022) had some very interesting results. The horse was had been exhibiting the oral behavior for 15 years. She was placed in therapy with commercially available isolated CBD 200 mg/ml at a dose of 0.5 mg/kg/ twice daily. Her hours spent exhibiting the behaviour were then recorded over a four week period. Amazingly, the time at which she spent wind sucking reduced drastically. According to the findings, on day one she spent up to 15 hours exhibiting the behaviour and after one week this fell to two hours. After the four week treatment, this fell to under an hour a day. The researchers also noted that the horse improved weight gain (from 400 kg to 452 kg) and showed a heathier coat. This findings are very positive in the effect of CBD on unwanted behaviours in horses.

What amount of CBD are in current brands supplements?

Below is a chart of the amount of CBD horses were fed and what effect it had according to the study’s results

This gives an indication as to the effects of CBD on horses. It must be remembered that CBD dosing in horses is still very much under review and needs further researching. Even though 1000mg was administered to the senior horses that reduced inflammatory responses, doesn’t mean a lower dose can’t also incur the outcome, it just hasn’t been tested yet. It must also be noted that time was also a factor, one out of the four studies was a single dose of CBD, while the others were longer periods of dosing.

Brands CBD Content

When looking at a CBD supplement for your horse, the CBD content and daily dosing are the two important factors to look at. Below is a chart of CBD supplement brands I could find online, that provided their CBD content.

As you can see from the chart, CBD content for a daily dose for a 500kg horse varies from brand to brand. It’s also so important to say, that the testing of the CBD needs to completed by a reputable, third party lab. If it isn’t, you want to ask yourself why the brand isn’t providing that information willingly. If you are looking to add CBD from these brands into your horses feed daily, below is the cost per day for a 500kg horse as advised by the brands.

Overall, it can be said that CBD has a place in the equine industry. It has been shown that it can affect horses resting heart rates, reactivity, behaviour and inflammatory responses. It is still a very new topic and further investigation is needed. If you are looking to add CBD to your horses diet remember:

1. Find the CBD content in mg
2. Find the daily dosage for your horse
3. Ensure the product is third party lab testing for authenticity and safety
4. CBD is still a FEI banned substance and may need a withdrawal period

References

Cohen, L., Jones, T., Guay, K., Smith, W. B., Nichols, J., & Elwonger, F. (2021). 62  evaluation of oral supplementation of Cannabidiol (CBD) in horses. Journal of Equine Veterinary Science, 100, 103525. https://doi.org/10.1016/j.jevs.2021.103525

Draeger, A. L., Thomas, E. P., Jones, K. A., Davis, A. J., & Porr, C. A. S. (2021). The effects of pelleted cannabidiol supplementation on heart rate and reaction scores in horses. Journal of Veterinary Behavior, 46, 97–100. https://doi.org/10.1016/j.jveb.2021.09.003

Turner, S., Knych, H. K., & Adams, A. A. (2023). The effects of cannabidiol on immune function and health parameters in senior horses. Veterinary Immunology and Immunopathology, 257, 110549. https://doi.org/10.1016/j.vetimm.2023.110549

Zamith Cunha, R., Felisardo, L. L., Salamanca, G., Marchioni, G. G., Neto, O. I., & Chiocchetti, R. (2022). The use of Cannabidiol as a novel treatment for oral stereotypic behaviour (crib-biting) in a horse. SSRN Electronic Journal. https://doi.org/10.2139/ssrn.4297457