With the use of hemp and cannabis products for humans on the rise, there is an increasing demand for research about how these products—specifically CBD—might be used in veterinary medicine. Though research is still scant, many pet owners have been turning to CBD products when conventional treatments fail. But is CBD safe?
Can You Give a Horse CBD?
CBD products are still very new on the equine scene, and researchers are only now starting to test the long-term effects that they might have on horses. In the meantime, while there is abundant anecdotal evidence in support of using CBD for horses, science has yet to catch up.
Given the lack of oversight from the FDA, take care when using products containing CBD on your horses. There is currently no guarantee of safety, and products may make inaccurate claims.
While CBD products geared toward equines are aggressively marketed online, many of their health claims—“improves gut health,” “reduces seizures,” etc.—have yet to be backed up by studies or scientific research. Some studies have shown benefits in small mammals and pets, but they are still inconclusive. Getting the right permits to do such studies is difficult—especially with equines—so it may take time before we have concrete answers.
But veterinary science is adapting to the rise in curiosity about the benefits of CBD for pets. VetCS—a CBD-focused company created and run by vets—is currently performing case studies to find out more about how cannabidiol affects equines. While they report incredible results, they also recognize the need for further studies in the field. According to equine veterinarian Dr. Chelsea Luedke, cofounder and Chief Veterinary Advisor of VetCS, “At VetCS, we look forward to playing an integral role in obtaining controlled studies and advancing our knowledge of cannabinoid use in horses to elucidate the reach of CBD therapy in different conditions.”
Do Horses Have an Endocannabinoid System (ECS)?
Yes—in fact, all vertebrates (and even some invertebrates) have them. The ECS is a neuromodulatory system made up of cannabinoid receptors (primarily CB1 and CB2 receptors), endocannabinoids, and the enzymes that synthesize and degrade endocannabinoids. Humans and animals naturally produce endocannabinoids that activate the receptors in the ECS—the same receptors that are stimulated by the exocannabinoids THC and CBD.
There are two main cell receptors in the ECS: CB1 and CB2. While they do intermix, they are concentrated in specific areas and have specific functions.
- CB1 Receptors: Located primarily in the brain and central nervous system, these receptors impact appetite, emotions, memory, and pain perception.
- CB2 Receptors: Concentrated in the GI tract and peripheral nervous system, these receptors modulate immune cell functions (e.g. potentially helping to reduce inflammation).
According to a 1999 study by the Institute of Medicine (now the National Academy of Medicine), CBD “appears to have a greater binding affinity for CB2 than for CB1”, but what this means for the uses of CBD remains to be seen. It is speculated, however, that CBD—which is less easily degraded by the ECS’s enzymes—allows the ECS to work harder and more productively to help animals ease a host of health issues (Getty, 2019).
What Does the Endocannabinoid System Do?
In short, the ECS helps maintain homeostasis. When the body feels that something is imbalanced, the ECS is activated to help correct it; for example, when we get too hot, the ECS responds by telling the body to sweat (via synthesized endocannabinoids), thereby cooling us down (Dellwo, 2019). The same goes for hunger (which tells the body to seek and ingest food), and so on.
Some of the functions regulated by the ECS include:
- Immune function
- Motor control
Endo- and exocannabinoids bind to the ECS’s cannabinoid receptors, where they continue to activate the ECS until they have been broken down by specialized enzymes. But while these enzymes are able to make quick work of the body’s endocannabinoids, they struggle to break down exocannabinoids like THC. This is why THC gets us “high” in a way that our own endocannabinoids don’t (Dellwo, 2019).
How Does Equine Digestion Affect CBD Dosing?
In spite of their large size, horses actually require fewer milligrams of CBD per kilogram body weight compared to other species. According to Dr. Luedke, CBD dosing should be both lower and less frequent in horses than in other animals. She notes that preliminary testing carried out by VetCS has “shown a longer half-life (8.5–9 hours) than what has been reported in dogs and humans.” This indicates the need for longer dosing intervals in horses than in other species.
“Horses also seem to be more sensitive on a per kilogram dosing model,” Dr. Luedke explains. “For example, doses of 1–2 milligrams per kilogram for a dog are common. Horses seem to be affected at lower dosing ranges, ranging from 0.25–1 milligram per kilogram.”
Hindgut Fermentation and CBD
This sensitivity is likely due to the way the equine digestive tract works; unlike humans, cats, and dogs, horses are hindgut fermenters. This means they get the vast majority of their energy from fermentation rather than digestion (the opposite of humans), and it may make them more susceptible to CBD.
The hindgut (also known as the large intestine) is comprised of the cecum and colon. It is a very delicate part of the equine GI tract that is subject to a host of health risks, from colic to ulcers. According to Kentucky Equine Research, sudden shifts in the bacterial flora that keep your horse healthy can be caused by “feeding too much grain, improper ratios of forage and grain, or moldy forage or grain,” but even something as seemingly innocuous as switching to a new type of hay can wreak havoc on the equine digestive system.
This is where introducing a new product like CBD into your horse’s feeding regimen can be risky. Many sites selling CBD products for horses claim that they can ease the symptoms of colic, but we are currently lacking data to support that claim. Considering how sensitive horses are to dietary change, discovering a safe and effective delivery method is key. Currently, there are many CBD oils and pellets for horses, though powders and pastes are also being explored.
To decrease the risk of GI issues, any feed changes—whether new hay or an inclusion like CBD in any form—should be integrated slowly (over a week or more) so that the hindgut’s microbiome can adapt. Providing your horse a constant supply of clean water and turning them out as much as possible can also help encourage a healthy GI tract. If any abnormalities occur, a vet should be consulted immediately.
What Is the CBD Dosage for Horses?
Although, the lack of CBD-related research in the equine field precludes official dosing advice, some product sites suggest dosing 0.55 milligrams per kilogram of body weight. Equine veterinarian Dr. Luedke explains that dosing 0.25–1 milligrams per kilogram is generally accepted, but notes that “[d]osing ranges are highly dependent on the condition affecting the horse.” She adds that while horses with anxiety might only require a single 125mg CBD dose (or less) 30–45 minutes prior to a stressful event (e.g. trailering, farrier appointments, etc.), horses experiencing a painful laminitic episode might require a daily dose of 500mg CBD until the pain improves. “These dosing ranges further support the need for knowledgeable advice from veterinary professionals,” she stresses.
If you choose to introduce CBD into your horse’s daily regimen, it should be incorporated gradually. Consider using stepwise dosing to slowly arrive at the optimal dose for your horse. Keep in mind that legality, product quality issues, and lack of solid research mean that there is no true dosing guide for equine CBD, so CBD products should be used with caution.
What Is the Optimal Delivery System for Equine CBD?
CBD products for horses range from oils and pellets to powder and paste, but which is most effective? According to Dr. Luedke, oromucosal administration via paste and especially powder is most effective in horses. She explains:
The gastric pH in the horse is notoriously difficult for absorption of nutraceuticals and pharmaceuticals; CBD is no different. Ideally, CBD is absorbed through the mucosa in the oral cavity. This route eliminates the first pass effect in the liver, which metabolizes CBD further before reaching the bloodstream.
Note: Cannabidiol powders and pellets are generally mixed with grain, while paste and oil are typically administered sublingually.
Will CBD Interact Negatively With My Horse’s Medications?
Trish Wilhelm CVT, VCC (Veterinary Cannabis Counselor) and Co-Founder and Chief of Operations at VetCS, asserts that VetCS’s equine case trials have not yielded any negative interactions between CBD and concurrent medications. She explains, however:
It is important to note that we do know cannabinoids are metabolized via [...] liver enzymes that are important for the clearance of various compounds[...]. This is important to us because any other drug that utilizes that same pathway system might be affected, but we don't exactly know how quite yet. Further studies will be important to understand drug interactions with CBD.
If your horse is currently taking other medications, Wilhelm says it’s important to follow the guidelines “start low and go slow” when it comes to dosing.
Could CBD Replace My Horse’s Medications?
The possibility that CBD products might one day replace medications with harsh side effects is exciting, but the research simply isn’t there yet. Dr. Luedke explains, “While we are not able to use CBD and hemp products as pharmaceuticals at this time for specific conditions, we have seen major improvements in horses suffering from chronic low grade inflammatory conditions.” She and the VetCS team have had good success in case studies where daily NSAIDs like Equioxx(R) were eventually replaced by hemp powder, and they have been able to decrease the daily dose of corticosteroids in horses with allergies by supplementing with CBD.
Unfortunately, replacing equine medications with CBD is not currently an option outside of these specialized case studies, and horse owners should consult with their vet before changing any medications.
Will CBD Get My Horse “High”?
Many horse owners are reluctant about giving their animals CBD, as they worry about any psychoactive effects their animals might experience. However, CBD products made for animals contain little to no THC (less than <0.3% THC by dry weight), so they are designed not to produce undesireable responses.
With that said, however, it’s important to remember that the full effects of CBD on horses are still unknown, so while they might not get “high” in the traditional sense, there may be other effects that have yet to be documented or reported.
What Equine Conditions Is CBD Good For?
Perceptions regarding the use of cannabis in horses are slowly changing in the medical field,and Wilhelm says that “There is absolutely a need for the use of CBD in horses.” She notes that VetCS has experienced positive responses to CBD for a wide variety of equine conditions, such as “anxiety (trailering, farrier appointments, trail rides, etc.), reduction of inflammation, promoting joint health, lameness issues, laminitis, allergies, and more.”
Anectodal evidence suggests that CBD may also alleviate other common equine ailments, including:
- poor digestion,
- low appetite,
- nervous disorders (e.g. cribbing),
- and leaky gut.
Unfortunately, these claims have not yet been backed up. Most animal-CBD research to date where some health benefits have been observed focused on mice, cats, and dogs (Wooten, 2018).
Can I Talk About CBD With My Vet?
As of now, California is the only state where veterinarians are legally able to discuss the use of cannabis in animals without the risk of losing their license (thanks to new legislation). However, they are not allowed to dispense or administer cannabis-related products.
“While veterinarians cannot currently legally prescribe or even recommend cannabis products to horse owners, they can bring awareness to the client of current veterinary cannabis research [...]. This is a wonderful opportunity to utilize a credentialed veterinary technician to bridge the gap of communication about cannabis in a clinic setting,” Wilhelm notes. Client inquiries about the use of cannabis for their pets are so frequent that companies like VetCS even offer clinics to coach credentialed veterinary technicians on how to legally speak about cannabis with clients.
Can I Give My Show Horse CBD?
Yes and no. If you compete at large shows, a positive result on a banned substance test could lead to a violation or worse. Consider the racing industry; the Racing Medication & Testing Consortium recently recommended “a mandatory purse redistribution, a 15- to 30-day suspension for the trainer, and possibly a fine for a CBD positive” (Patton, 2018, p. 9). The United States Equestrian Federation (USEF) has a strict anti-cannabinoid policy as well.
As CBD products become more prevalent, these rules and regulations will continue to evolve, but for now, avoid giving your horse any CBD products—hemp-derived or otherwise—while on the show circuit.
What Is CBD and How Is It Different From THC?
CBD (cannabidiol) is a chemical compound derived from the Cannabis sativa plant. Long ignored in favor of THC (tetrahydrocannabinol), the second major chemical compound found in the cannabis plant, CBD has recently come to the fore. Unlike THC, CDB does not produce undesirable psychoactive effects, meaning that users can take advantage of its benefits without feeling “high.”
Hemp and marijuana are two varieties of the same plant species, and CBD can be derived from either one. But while hemp-derived CBD was federally legalized in the Agricultural Act of 2018, cannabis-derived CBD is still considered a Schedule I controlled substance (though the first FDA-approved drug containing cannabis-derived CBD—Epidiolex—was placed in Schedule V of the Controlled Substances Act in June of 2018).
Contains 0.3% or less THC (by dry weight)
Contains more than 0.3% THC (by dry weight)
Harvested to produce a wide variety of products, from paper and cooking oil to CBD-infused lotion
Primarily used for recreational purposes, with an increasing focus on medicinal applications
Grows easily (usually outdoors)
More difficult to grow (must be bred and grown in controlled environments)
An Exciting Future for Veterinary CBD
Though the exploration of CBD use in animals is still in its early stages, research has been promising so far. More studies and changes in legality are sure to emerge as CBD use continues to gain traction in human and veterinary medicine.
If you are interested in including CBD in your horse’s diet, be careful about which products you use. Some cannabis-derived CBD products contain small amounts of THC, and the FDA has found much variance in the products they have tested. In dogs and cats, it is believed that CBD-to-THC ratios of 20:1 and 18:1 are likely safe due to the low amount of THC, but the equine response to THC remains unknown.
Here are some tips for choosing a safe product:
- Request a Certificate of Analysis (CoA) or the complete profile of the final product.
- Verify that no pesticides or fungicides were used in production.
- Look for a mycotoxin and heavy metal analysis.
- Abide by the rule “start low and go slow” and slowly increase to effect.
- Make sure the company is providing third-party lab testing to ensure the product contains no residual solvents left over from the extraction method (e.g. alcohol).
- Keep a record of your pet’s response to the product.
Important: Alcohol-based tinctures are not okay for use in pets.
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