By Gary Richter, MS, DVM; Posted with permission from

Gary Richter, MS, DVM, CVA, CVC, GDWVHM, a Project CBD contributing writer, is an Oakland-based veterinarian. His articles focus on practical information for using cannabis to treat medical conditions in pets.

Any animal with a backbone (classified as a chordate) has an endocannabinoid system. The Kingdom of Chordata includes amphibians, reptiles, birds, fish, and mammals, including house pets. Many animal-owners treat their beloved pets like family members. When a dog or a cat gets sick and conventional options don’t work, people seek alternatives. In the realm of natural healing, cannabis for animals seems like a logical botanical pathway to explore.


In the big picture, the endocannabinoid systems of pets and people are very similar. One striking difference is there appears to be a greater concentration of cannabinoid receptors in the dog’s brain than there are in most other animals. This is significant because it makes dogs more susceptible to THC overdose, potentially giving them a certain amount of neurologic impairment in the short-term. This phenomenon is known as static ataxia. Otherwise, when cannabis medicine is used effectively, their endocannabinoid system will act in the same way it would for a human.


Conventional pharmaceuticals commonly used to treat pain sometimes have a negative impact on the immune system, GI tract, liver, and kidneys. Additionally, they don’t always work as well as we would like them to – for humans as well as our pets.

Of all the uses of cannabis in human and veterinary medicine, pain relief is perhaps the most well documented. Research trials have shown profound pain-relieving effects from cannabis for a variety of medical conditions. Extracts of THC and CBD have been shown to provide relief in human patients with advanced cancer pain as well as in those with nerve related pain.

Studies evaluating the efficacy of cannabis in treating arthritis in dogs have been completed as well. A recent study from Cornell University showed reduction in pain scores in dogs with arthritis – with no negative side effects – when treated with CBD vs. placebo. In a more practical sense, many veterinarians and pet owners have seen the positive effects of medical cannabis for the treatment of arthritis and other forms of pain in animals. The research merely confirms what many of us have seen first-hand.


Medical cannabis for pets usually comes as a liquid oil or as treats. Liquids are preferable because the dosing can be accurately controlled and because CBD may be better absorbed through the tissues of the mouth rather than through the digestive tract.

Vaporized or smoked cannabis should NEVER be used with pets. This can damage their lungs and can lead to accidental overdose.

Similarly, edibles for humans should not be given to your pet as they are impossible to dose accurately and they may contain ingredients (such as raisins, chocolate, etc.) that are toxic to animals.


Always consult with your veterinarian before beginning cannabis therapy for your pet.

Ratios of THC to CBD range from as high as 20:1, to even ratios (1:1), to 1:20. The decision of which product or ratio to use for a pet with pain or inflammation often depends on the severity of the pain and its origin.

  • High CBD ratios (4:1 to 20:1 CBD-to-THC) are best for anxiety and mild to moderate pain such as arthritis and back pain.
  • A balanced ratio (1:1 CBD to THC) is best for moderate pain such as arthritis and back pain.
  • High THC ratios (4:1 to 20:1 THC-to-CBD) are used for severe pain such as cancer pain, nerve pain, and advanced arthritis.

CBD Dosing

0.5 – 5 mg CBD per 10 pounds of body weight twice daily.

Start low and slowly increase the dose every 4-7 days. Frequently doses nearer the lower end of the range are effective. Higher doses of CBD may be beneficial in certain circumstances.

THC Dosing

0.2 – 0.6 mg THC per 10 pounds of body weight twice daily.

THC is always the limiting factor when dosing. Start low and slowly increase the dose every 4-7 days. Higher doses may be possible/necessary on a case-dependent basis. Monitor closely for sedation, loss of balance, or loss of mental acuity. Decrease the dose or discontinue immediately if any side effects are seen.

When using cannabis as medicine for pets, the first thing to remember is that any significant side effects are unacceptable. Getting your dog or cat stoned is never OK, even with medical cannabis. The goal with cannabis therapy in pets is to relieve the symptom being treated with no other side effects. Their normal patterns of behavior should be unaltered after receiving the therapy.


In ancient times, cannabis was used for seizures based purely on observational data, but today in-depth scientific research is being conducted to determine how and why cannabis is beneficial in the effort to determine how best to limit, and hopefully eliminate, seizures. Anecdotal reports from pet owners and veterinarians suggest that cannabis can not only reduce seizure frequency, it may be able to lessen seizure severity, shorten recovery time, and potentially even prevent an imminent seizure if the animal is medicated at the first signs of trouble.

The first published clinical trial evaluating the effects of CBD on seizures in epileptic dogs, conducted at Colorado State University, evaluated seizure frequency in dogs with and without the use of CBD. Results showed an 89% reduction in seizure frequency in dogs who received 2.5 mg/kg CBD twice daily compared to a 43% reduction in dogs not receiving CBD. Both groups of dogs were receiving other anti-seizure pharmaceuticals at the time of the study which is the reason the group not receiving CBD had a large reduction in seizures, as well.

With research ongoing, we certainly see promise in the use of CBD, and potentially other cannabinoids, for the treatment of seizures in animals. That said, cannabis as medicine should be used with caution. CBD given at moderate to high doses can potentially effect blood levels of other medications, including anti-seizure drugs. Because of this, it may be necessary to monitor levels at the beginning of cannabis therapy.


As with humans, the road to medical acceptance for animal use has been slow. In Sept 2022, veterinarians in California were finally granted explicit permission via the passage of California’s AB1885 to “recommend” medical cannabis products for their pet patients without threat of having their license revoked. This is a critical and obvious first step toward acceptance, but as a result of decades of censorship about what vets could and couldn’t discuss, there’s an unfortunate lack of understanding and expertise among most vets practicing today. This bill requires the Veterinary Medical Board to adopt and publish recommendation guidelines by January 1, 2024; fully tested, state-approved medical cannabis pet products will be coming to dispensaries, under new rules from the Department of Cannabis Control, no later than July 1, 2025.

Despite this slow regulatory trajectory, we have been treating our own pets with tinctures with great success for many years. Sespe Creek carries several tinctures formulated by vets especially for pets; ask your vet if these would be appropriate for your pet.


Many people start with hemp products because of their relative ease of accessibility. But in many cases, we don’t know the source of the CBD in these products. Do your due diligence as you would with any vitamin or supplement. Call the company and ask where the product is coming from and how it’s being produced. There is no government oversight to make sure that these companies are selling authentic and safe products. A pet owner’s only other option is to get a card and go to a medical marijuana dispensary if they want something that may be more effective than hemp-derived CBD.

Ideally, you would look for a product that is organic and produced locally. You want to know how the CBD was extracted and the full spectrum of cannabinoids that are present. CBD products purchased at a licensed dispensary must be lab tested according to much more rigorous standards.


Obviously whenever we’re talking about THC and pets, dosing becomes very important. At no point is the goal for the pet to get stoned. If that happens, then it means they’ve gotten too much. The aim is to give them enough cannabis to be effective, but not so much that they’re going to be negatively compromised. It is extremely uncommon to see an animal show negative signs when they have been properly dosed with cannabis as medicine. The worst effect would be drowsiness. If that’s that case, the owner may have to decrease the dose.

It’s not uncommon for a dog, or sometimes a cat, to show up at a veterinary hospital having eaten a cannabis-infused edible that belonged to the owner. The good news is that cannabis toxicity is nonfatal and does not cause long-term effects. However, those animals that get into their owner’s stash may require immediate medical care.

“I have seen and heard of a couple of cases where pets did not survive,” says Gary Richter, a veterinarian. “One case that I have personally seen was a dog that got into a bunch of cannabis edibles and the owner didn’t bring his dog to the veterinarian immediately. They called us the following day. Unfortunately, the dog had vomited and aspirated while at home, his lungs filled with fluid, and he wound up dying from a systemic infection related to that. To be honest, if this dog had received medical treatment the day he ate cannabis, he almost certainly would have been fine. It was only because the owner waited, and by that time it was too late. It was very sad. But this type of event is really quite rare.”


If you decide to give your pet cannabis medicine, get informed. The medicine you give your animal should have the same standards for anything you would put in your own body. Make sure the product is safe and tested for cannabinoid content, quality, and is free from any contaminants or additives. Seek guidance from a vet, if at all possible, at (American Holistic Veterinary Medical Association) or

Learn more about treating your pets with cannabis in this video featuring Dr. Eileen Guillen DVM – Mon, Oct. 14, 2019