There is a lot of discussion around cannabidiol (CBD) in veterinary medicine due to its potential to control some diseases in both human and veterinary medicine. As a researcher undertaking CBD and cannabidiolic acid (CBDA – the precursor molecule to CBD found in the plant) research, I suggest that you discuss a number of factors regarding cannabis with your veterinarian before using a product. A survey in Frontiers in Veterinary Science suggested that approximately 50 percent of vets did not feel comfortable discussing cannabinoid use with their clients, but this is slowly changing. Last year three review articles on the use of cannabinoids were published in the Journal of the American Medical Association which covered: quality and regulation; possible indications in dogs; and the known pharmacokinetics in dogs. They are great resources and will be summarized here.

Is the product of known quality?

Quality control is an important concern in the hemp industry. Products for pets should be made from certified hemp crops which will ensure that they fall within the federal guidelines for hemp as having less than 0.3 percent THC (the molecule from Cannabis that makes you feel “groovy”). If over 0.3 percent THC, then a crop is considered marijuana and, in some states, must be destroyed. All of the other known cannabinoids in hemp do not have psychotropic actions at typical levels found in products. There are over 100 derivatives of cannabinoids with CBDA and THCA usually found to be the most prominent in hemp and marijuana, respectively. CBDA and THCA are not the same as CBD and THC; however, when plants are heated during extraction into the oils you find in the market, these acids will be turned into CBD and THC. 

In 2020 we published a study examining the levels of cannabinoids found in commercial products and found that they were highly variable, but all products contained less than 0.3 percent THC meeting the federal guidelines. The concentrations of CBD (and/or CBDA) in these products were between 0-70 mg/mL, with most being in the 20-25 mg per ml range. However, cannabinoid content is not the only thing to be concerned about; as with any other crop we want to know about heavy metal, pesticide and extraction solvent contamination, as well as potential contamination with pathogenic bacteria and mycotoxins, all of which can cause health issues. That being said, a good company will provide a third-party analysis that you and your vet can examine, and they will not release a product without this sort of testing. This is a good starting point for a safe product -- i.e., examination of the label.

Is CBD-rich hemp safe to give?

There are now about a dozen studies looking at short- and long-term dosing of cannabinoids in dogs. Some products contain CBD, while others contain a spectrum of hemp products which have other cannabinoids like CBDA or CBG (two other popular ones) with THC minimized in the product. Some products contain a full spectrum and will have other molecules like flavonoids and terpenes. Safety studies across these various compositions at doses up to 10 mg/kg a day for up to 36 weeks suggest it is largely safe to provide long term. The National Animal Supplement Council (NASC) looked at the effects of a broad-spectrum CBD (meaning other molecules from the plant, plus primarily CBD) -- a blend of CBD/CBDA and a blend of CBG/CBD. They reported that it was safe to provide for three months every day at a dose of five mg per kg body weight. More importantly, NASC is an industry regulatory body that good companies will join, and the organization will audit the company for good manufacturing, accuracy of label and adverse events. NASC found less than two reports of adverse events per one million products sold each year for the past 10 years, which is encouraging. Similar to other supplements, adverse events tend to be issues like vomiting and diarrhea, with somnolence, lethargy or behavioral changes as other potential adverse events that owners should be aware of. 

Regulatory guidelines

Recently, the American Association of Veterinary State Boards developed guidelines for veterinarians which outline aspects of safety and quality control. Their guideline is to pick a product that has efficacy data based on the state in which its distribution is legal. For guidance on the regulatory landscape and advice on recommending the use of CBD supplements in dogs, there are several readily available websites for you and your veterinarian, for example, An Update on the Legal Considerations of the Use of Cannabis in Veterinary Medicine | Today's Veterinary Practice (todaysveterinarypractice.com). Note that the legal counsel of this article advises ElleVet Sciences, which markets the product for veterinary use. The only effectiveness claims that can be made must be based on peer reviewed and preferably, double-blind, placebo-controlled studies which I have summarized below, supplemented with references.

What research shows promise for helping clinical disease? 

Recent studies from the United States showed efficacy for improving mobility related to arthritis pain. Two of those products are primarily broad-spectrum products of about 20 mg/ml given at doses between 1-2 mg per kg body weight. The third is a product that was given at 2 mg/kg as a full spectrum product containing an equal mix of CBD/CBDA.

CBD is used in children with uncontrolled seizure disorders, but there is less data surrounding the treatment of uncontrolled seizures in dogs. Two studies in the literature showed that a broad-spectrum, CBD-rich hemp product reduced seizures compared to placebo treatment by 25-30 percent at a dose of 4.5 mg/kg twice a day. Similarly, another study showed that 2 mg/kg twice a day of a full spectrum CBD/CBDA mix resulted in a 42 percent reduction in clinically significant seizures.

Lastly, there is a single well-designed study looking at itching (pruritus) in dogs with atopic dermatitis; it showed that approximately 65 percent of dogs responded to a full spectrum CBD/CBDA product with clinically significant reduction in itching when used at 2 mg/kg every 12 hours compared to placebo. The nervous system is ramped up for itching, just like it is for pain – so, there is logic in its use in this scenario.

There is anecdotal evidence that CBD products may be helpful to reduce anxiety symptoms. However, the studies using CBD for anxiety are weak and suggest only mild positive effects that an owner might not pick up on. It is likely that dosing may need to be higher than that proposed. There has not yet been a double-blind, placebo-controlled clinical anxiety study published in the veterinary literature. 

References 

Henion J et al: Key quality control aspects about cannabinoid-rich hemp products that a veterinarian needs to know: a practitioner’s guide. J Am Vet Med Assoc. March 2023

Verrico CD et al: A randomized, double-blind, placebo-controlled study of daily cannabidiol for the treatment of canine osteoarthritis pain. Pain. 2020 Sep 1;161(9):2191-2202.

Rozental AJ et al: The efficacy and safety of cannabidiol as adjunct treatment for drug-resistant idiopathic epilepsy in 51 dogs: A double-blinded crossover study. Vet Intern Med. 2023 Nov-Dec;37(6):2291-2300

McGrath S et al: Randomized blinded controlled clinical trial to assess the effect of oral cannabidiol administration in addition to conventional antiepileptic treatment on seizure frequency in dogs with intractable idiopathic epilepsy. J Am Vet Med Assoc. 2019 Jun 1; 254(11):1301-1308

Bookout W et al: Safety study of cannabidiol products in healthy dogs. Front Vet Sci. 2024 Mar 1; 11:1349590

Corsato Alvarenga I et al: Tolerability of long-term cannabidiol supplementation to healthy adult dogs. Vet Intern Med. 2024 Jan-Feb; 38(1):326-335

Gamble LJ, Boesch JM, Frye CW, Schwark WS, Mann S, Wolfe L, Brown H, Berthelsen ES, Wakshlag JJ. Pharmacokinetics, Safety, and Clinical Efficacy of Cannabidiol Treatment in Osteoarthritic Dogs. Front Vet Sci. 2018 Jul 23:5:165. 

Loewinger M et al: The effect of a mixed cannabidiol and cannabidiolic acid based oil on client-owned dogs with atopic dermatitis. Vet Dermatol. 2022 Aug;33(4):329-e77.  

Schwark WS, Wakshlag JJ: A One Health perspective on comparative cannabidiol and cannabidiolic acid pharmacokinetics and biotransformation in humans and domestic animals. Am J Vet Res. 2023 Mar 29; 84(5)

Garcia GA et al: Safety and efficacy of cannabidiol-cannabidiolic acid rich hemp extract in the treatment of refractory epileptic seizures in dogs. Front Vet Sci. 2022 Jul 29; 9:939966
Brioschi FA et al: Oral Transmucosal Cannabidiol Oil Formulation as Part of a Multimodal Analgesic Regimen: Effects on Pain Relief and Quality of Life Improvement in Dogs Affected by Spontaneous Osteoarthritis. Animals (Basel). 2020 Aug 26; 10(9):1505

Updated Aug. 2024