CBD is generally safe for both dogs and cats at appropriate doses. Safety trials lasting up to six months show that pets tolerate it well, even at relatively high doses. That said, no CBD product has been approved by the FDA for use in animals, and the biggest real-world risks come not from CBD itself but from poor-quality products contaminated with THC or other unlabeled compounds.
What the Safety Research Shows
Multiple veterinary safety studies have tested CBD in dogs and cats at doses up to 10 mg per kilogram of body weight per day for as long as 36 weeks. At those levels, CBD appears to be well tolerated with minimal serious effects. The National Animal Supplement Council has reported that daily doses of 5 mg per kilogram are safe for at least three months of continuous use.
The main physiological concern is liver health. High doses of CBD can raise liver enzyme levels in both dogs and cats, which signals the liver is working harder to process the compound. This is typically mild and reversible, but it matters more if your pet already has liver issues or takes medications that are processed through the liver. CBD can also interfere with how the body metabolizes certain drugs, potentially making other medications stronger or weaker than intended. If your pet is on any prescription medication, that interaction is worth discussing with your vet before adding CBD.
Pets with moderate to severe heart disease need extra caution. Veterinary experts recommend monitoring heart function with a cardiologist a few weeks after starting CBD in those cases.
Side Effects to Watch For
When side effects do occur, they tend to be mild. The most common one is drowsiness. In cases reported to poison control databases, about 30% of pets given CBD showed lethargy, 21% had trouble with coordination, and 6 to 7% experienced trembling, heightened sensitivity to touch, or urinary incontinence.
Here’s the important nuance: many of those reactions likely weren’t caused by CBD alone. Researchers attribute those symptoms to either massive quantities of hemp product (which contains trace THC that adds up at high volumes) or, more commonly, to products that were contaminated with unlabeled THC or synthetic cannabinoids. When a pet shows signs that look more like THC intoxication, such as severe unsteadiness, disorientation, or unresponsiveness, the product itself is usually the problem.
THC Is the Real Danger
Dogs are far more sensitive to THC than humans. Even small amounts can cause intoxication, and concentrated products like oils or edibles can lead to severe reactions. Legal hemp-derived CBD products must contain less than 0.3% THC, which is a very small amount, but cheap or unregulated products don’t always meet that standard.
Signs of THC toxicity in pets include extreme lethargy, loss of coordination, drooling, vomiting, and in serious cases, tremors or seizures. If your pet shows these signs after taking a CBD product, the product likely contains more THC than labeled. That’s a veterinary emergency, not a normal CBD side effect.
Conditions Where CBD May Help
The strongest evidence for CBD in pets involves osteoarthritis pain in dogs. A clinical trial at Cornell University found that dogs given CBD oil showed significant decreases in pain scores and increases in activity levels within two weeks, and those improvements held through the four-week study. Pain scores dropped from an average of 21 out of 40 at baseline to 14 during CBD treatment, while dogs on placebo showed no change. Veterinary assessments confirmed the same pattern.
For seizure disorders, two studies found that broad-spectrum CBD reduced seizure frequency by 25 to 30% at a dose of about 4.5 mg per kilogram twice daily. A full-spectrum product containing both CBD and its raw precursor form achieved a 42% reduction in significant seizures at a lower dose. CBD doesn’t replace anti-seizure medication, but it may reduce how often breakthrough seizures occur.
Itching and skin allergies have also shown promising results. About 65% of dogs in one trial had a meaningful reduction in itching when given a full-spectrum product at 2 mg per kilogram twice daily, compared to placebo. Typical doses used in arthritis studies are lower, around 1 to 2 mg per kilogram.
Dogs Versus Cats
Most CBD research has been conducted in dogs, and the evidence base for cats is thinner. Both species have the same type of receptor system that CBD interacts with, and safety trials have included both dogs and cats without identifying dramatically different risk profiles. However, cats metabolize many substances differently than dogs, and they’re generally more sensitive to compounds that are processed through the liver. If you’re giving CBD to a cat, starting at the lower end of any dosing range and watching closely for excessive sedation is a reasonable approach.
How to Choose a Safe Product
Product quality is the single biggest safety variable. The CBD pet market is unregulated, and independent testing has repeatedly found products that contain more or less CBD than labeled, higher-than-legal THC levels, or contaminants like heavy metals and pesticides. A Certificate of Analysis (COA) from a third-party lab is the only way to verify what’s actually in a product. If a company doesn’t provide one, skip it entirely.
When reading a COA, look for these key sections:
- Cannabinoid potency: The total CBD should be within 10% of what the label claims. THC should be below 0.3%, and for pets, the lower the better.
- Heavy metals: The report should test for lead, mercury, arsenic, and cadmium. Results should say “ND” (not detected) or fall well below acceptable limits.
- Pesticides: A thorough panel screens for dozens of individual pesticides. You want “ND” across the board.
- Residual solvents: Products made with CO2 extraction, which is considered the gold standard, should show no detectable solvents.
- Microbial testing: Should confirm no E. coli, Salmonella, or excessive mold and yeast.
Products labeled “full spectrum” contain small amounts of other naturally occurring hemp compounds alongside CBD. “Broad spectrum” products have most of those compounds with THC removed. Isolate products contain only CBD. Clinical trials in pets have used both broad-spectrum and full-spectrum formulations with positive results.
The Regulatory Situation
As of early 2025, no CBD product has received FDA approval, conditional approval, or indexing for use in animals. That means CBD products marketed for pets exist in a legal gray area. They can’t legally claim to treat, cure, or prevent any disease. Veterinarians in many states face restrictions on recommending or prescribing CBD, though the landscape is gradually shifting. The FDA issued a formal request for information on cannabis-derived products in veterinary practice in January 2025, signaling that regulatory frameworks may eventually catch up to the science and the market reality.
The practical consequence for pet owners is that you’re largely navigating this on your own. Choosing products with verified COAs, starting with low doses, and monitoring your pet’s behavior and energy levels closely are the most important steps you can take to use CBD safely.