CBD for Pets: What Veterinary Research Shows

It hurts to see your aging dog struggle up the stairs, tremble on fireworks nights or have seizures. As more and more CBD oils and treats are sold for pets, it’s only natural to wonder, "Would this help my companion?" In this article, we’ve gathered veterinary research in dogs and cats, the side effects seen, why THC is a separate danger, and the topics you can discuss with your veterinarian.

Why is CBD for pets a topic of discussion?

CBD (cannabidiol) is a substance found in the cannabis plant that does not cause a high or mental fogginess. After research in humans sparked interest, CBD products also began to be marketed for dogs and cats for problems such as pain, anxiety, seizures and itching.

The US Food and Drug Administration (FDA) states that it has not approved cannabis products for any use in animals and cannot guarantee the safety or effectiveness of these products; it advises pet owners to talk with their veterinarians about appropriate treatment options for their pets. In other words, these products have not gone through controlled studies the way approved (licensed) veterinary medicines have.

What does research in dogs say?

The best way to show whether a treatment works is a controlled study: animals are randomly assigned to groups, one group receives CBD and the other an oil that looks the same but has no active effect (a placebo), and neither the owners nor the veterinarians know which group is getting what. There are studies of this kind in dogs, but they are few, and most are small.

Osteoarthritis

• Gamble 2018: In a crossover study that started with 22 dogs with osteoarthritis, 16 of which completed it, the dogs took CBD oil for four weeks and a placebo for four weeks, in turn. During the CBD period, improvements were seen on the pain and mobility scales filled out by the owners and in the veterinarian’s pain assessment. There was no difference, however, in the veterinarian’s lameness score or in the ability to bear weight on the leg. Owners reported no side effects, but in blood tests, alkaline phosphatase (ALP), a liver enzyme, rose in 9 of the 16 dogs. The study was carried out with support from the company that made the product.
• Verrico 2020: In a four-week controlled study in dogs with osteoarthritis, CBD reduced pain and improved mobility; the effect increased with the dose. Blood tests at four weeks showed no harmful changes. One of the authors is a consultant to a CBD company.
• Mejia 2021: A crossover study of 23 dogs also used objective measures such as gait analysis and activity monitors. No measure showed a difference between CBD and placebo. During the CBD period, liver enzymes rose in 14 dogs and 2 dogs vomited.

In an analysis combining these studies, all 5 studies, covering 117 dogs, were found to have a high risk of bias. It concluded that CBD may reduce pain scores, but that the certainty of this evidence is very low. In the short term, CBD was generally well tolerated; the most common findings were vomiting and a rise in ALP that caused no symptoms (Patikorn 2023).

Epilepsy

• McGrath 2019: 26 dogs whose seizures continued despite seizure medicines were divided into two groups; one group received CBD on top of their current medicines, and the other received a placebo. 2 dogs in the CBD group were withdrawn from the study because of loss of balance (ataxia); 9 CBD dogs and 7 placebo dogs were included in the analysis. In the CBD group, seizure frequency dropped by a median of 33%. However, the proportion of dogs whose seizures fell by at least half was similar in the two groups. ALP rose in the dogs taking CBD.
• Rozental 2023: In a crossover study of 51 dogs with drug-resistant epilepsy, the lower dose was dropped because it did not work well enough in the first 12 dogs. At the higher dose, the number of days with seizures fell by 24.1% during the CBD period, while it rose by 5.8% during the placebo period. There was no difference in the proportion of dogs whose seizures fell by at least half. Liver enzymes rose at both doses; decreased appetite and vomiting were more common during the CBD period. The researchers recommend monitoring liver enzymes in dogs taking CBD.

In a study in healthy dogs, no clear interaction in blood levels was found between CBD and phenobarbital, a commonly used seizure medicine; however, some dogs given CBD had stomach and bowel complaints and a rise in ALP (Doran 2021).

How was it given?

In a study in healthy dogs, CBD oil given by mouth produced higher CBD blood levels than capsule-like beads or a cream applied to the skin (Bartner 2018). This study measured only how much reached the blood, not effectiveness.

What is known about cats?

There is much less research in cats than in dogs. A review of studies in dogs and cats found 22 publications, only two of which were about cats. The authors stress that long-term effectiveness, appropriate amounts and safety are still unclear (Moreno-López 2025).

In controlled studies in healthy cats, a THC-free CBD product was given with food every day for up to 26 weeks. In the first four-week study, a liver enzyme (ALT) measured higher in the CBD group than in the placebo group; in the 26-week study, however, the groups were similar in terms of liver enzymes, and the product was generally well tolerated (Coltherd 2023). The researchers were employees of a pet food manufacturer, and these studies looked at safety in healthy cats, not effectiveness.

Possible side effects and the danger of THC

The most commonly reported findings in dog studies were:

• Raised liver enzymes, especially ALP,
• Vomiting and decreased appetite,
• Loss of balance in some dogs.

The real danger, however, is THC. THC, the intoxicating substance in cannabis, is toxic to dogs and cats. At two veterinary hospitals in the US, the number of dogs brought in with cannabis poisoning increased fourfold over five years; two dogs that ate cakes and cookies made with THC butter died (Meola 2012). According to the FDA, an animal that has eaten a cannabis product may show sluggishness, lethargy, heavy drooling, vomiting, restlessness, tremors and seizures. If you notice any of these signs, contact your veterinarian or an animal emergency clinic right away.

On CBD products sold for people, the label does not always match the contents; THC was found in about one in five of 84 products bought online (Bonn-Miller 2017). We explain how to read a label on the label-reading page . We also cover the risks of edible cannabis products for children and pets in our article on edible CBD .

How was it used in the studies?

In most dog studies, CBD was given by mouth as an oil, twice a day; the studies lasted between 4 and 12 weeks. In the epilepsy studies, CBD was added alongside the dogs’ seizure medicines, not used instead of them. The amounts used varied from study to study, and the products were different (full-spectrum oil, pure CBD, liposomal CBD). No effective and safe amount of CBD has been established for dogs or cats; on this site, we don’t recommend doses for pets either.

If you are thinking about CBD for your pet

It’s only natural to want your companion to feel more comfortable. You can talk with your veterinarian about these topics:

• The cause of your animal’s complaint and treatment options that have been shown to work.
• All the medicines it takes, especially seizure medicines and painkillers.
• If CBD is to be given, whether liver enzymes will be checked before starting and during use.
• Whether the product contains THC and how its contents can be verified.
• If you have a cat, that studies done in dogs cannot be applied to cats.

Don’t give your pet a product sold for people on your own initiative, and don’t reduce or stop seizure medicines without consulting your veterinarian. In Turkey, cannabis-derived products, including CBD, can be sold only in pharmacies (Law No. 7557, regulation of January 31, 2026). Those classed as medicines and health products are dispensed with a prescription; for supplement products with a THC content of no more than 0.3%, no prescription requirement is stated. As of October 2026, there is no approved (licensed) CBD medicine in Turkey. For details, see the regulations page.

Conclusion

Small studies of osteoarthritis and epilepsy in dogs show mixed results alongside promising signs; raised liver enzymes, however, are a common finding seen in almost every study. Information in cats is even more limited, and products containing THC are toxic to both species. If you are thinking about CBD for your pet, consult your veterinarian, who knows your animal’s weight, illness and medicines.

Frequently asked questions

References