Are CBD supplements BAD for your PET?

By Dr. Beth Leermakers

CBD is all the rage in the pet industry. When I mentioned to a dog treat vendor that one of my dogs is very fearful of strangers, the woman immediately recommended CBD treats. My dog, who has been evaluated by a wonderful trainer who specializes in fearful dogs, isn’t anxious. He just has stranger danger — something that is not likely to be fixed by a supplement. 

I am skeptical of supplements — for people or animals — that aren’t supported by scientific evidence and are regulated by the Food and Drug Administration (FDA). Before I spend money on a supplement, I want to know that it’s safe and effective. So, I investigated whether there’s any scientific merit to CBD products for cats and dogs. 

What is CBD?

Cannabidiol (CBD) is a “cannabinoid” — a chemical compound derived from the cannabis (marijuana) plant. Tetrahydrocannabinol (THC), the other commonly known cannabinoid, is the component that produces the “high” associated with marijuana use. Unlike THC, CBD doesn’t produce a high and is not psychoactive. 

CBD shares important metabolic pathways with non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and Rimadyl (a pain reliever). These pathways control many processes in the body, from inflammatory responses to blood clotting. People use CBD because of its anti-inflammatory properties, cardiac benefits, anti-nausea effects, appetite stimulation, anti-anxiety impact — and for possible anti-cancer benefits, although there’s no conclusive data on this use. 

The FDA has only approved one CBD product, a prescription drug product to treat seizures associated with Lennox Gastaut syndrome (LGS), Dravet syndrome (DS) or tuberous sclerosis complex (TSC) in people one year of age and older.

Does CBD have health benefits for cats and dogs?

Maybe. CBD has been advertised as managing anxiety, seizures, cancer and pain in dogs and cats. However, scientific evidence supporting the effectiveness of CBD for cats and dogs is limited — particularly for cats. 

CBD may be effective for:

Pain reduction. One double-blinded, placebo-controlled (i.e., rigorous) veterinary study found that CBD significantly decreased pain and improved mobility in large dogs with osteoarthritis. The researchers didn’t find any harmful effects of CBD administration throughout the 4-week study period — based on blood tests that measured red blood cells (having too few or too many can be a sign of disease) and liver and kidney function. 

In another study, 16 dogs with osteoarthritis took CBD oil twice a day for four weeks. Pain and activity questionnaire scores indicated a significant decrease in pain and increase in activity with CBD oil. Veterinary assessment showed decreased pain during CBD treatment. The dogs’ owners didn’t report any side effects, but serum chemistry showed an increase in liver enzymes during CBD treatment. This study suggests that CBD oil can increase comfort and activity in dogs with osteoarthritis. 

Reducing the frequency of seizures. One randomized, controlled study of 26 dogs with epilepsy examined the impact of CBD oil on the frequency of seizures. Twelve dogs randomly assigned to the CBD group took CBD oil twice a day for 12 weeks in addition to their existing antiepileptic medication. Results indicated that Dogs in the CBD group had a significant reduction in seizure frequency, compared with the placebo group. 

Is CBD Safe for 

Cats and Dogs?

Yes — but there may be side effects. One uncontrolled study examined the safety and adverse effects of giving an oral CBD product to eight healthy adult cats and eight healthy adult dogs for 12 weeks. The study veterinarian examined all the subjects before the study and then weekly during it. Adverse events — including vomiting, loose stool, pain and distress — were noted regularly. 

None of the animals experienced any significant changes in blood chemistry values or weight, loss of appetite, or behavioral changes during the 12-week period. However, mean alkaline phosphatase (ALP; a liver enzyme) levels rose consistently and sequentially in dogs, though staying within the reference range. Cats experienced similar rises in alanine aminotransferase (ALT; a liver enzyme). Researchers concluded that CBD appears safe in healthy dogs and cats. However, adverse effects were seen in both cats and dogs, including mild clinical signs and modest elevations in liver enzymes. 

Are CBD Products 

Legal for Animals?

No. According to the FDA, it is not legal to sell a food (including pet food) to which CBD or THC has been added. The FDA does not have control over supplements for animals. Since the FDA doesn’t regulate supplements containing CBD, they can’t guarantee their safety or effectiveness. CBD products can contain ingredients that aren’t listed on their labels — including THC, which is toxic to cats and dogs. The FDA discourages the use of CBD in pets because of insufficient data on appropriate dosing, long-term effects on serum chemistry (e.g, liver enzymes), and pharmacokinetics (e.g. how CBD is absorbed, distributed in the body and excreted). U.S. veterinarians are forbidden from prescribing/dispensing CBD, and they cannot encourage or instruct clients to purchase CBD products.

The bottom line? CBD may have health benefits, but more research is needed — particularly in cats — regarding its effectiveness and to be sure it’s safe for long-term use. If you choose to give your cat or dog CBD products, proceed with caution, after discussing the potential risks/benefits with your veterinarian.