If your dog ate a joint, the THC in it will likely make them visibly sick within 30 minutes to a few hours. The good news: most dogs recover fully with supportive care. The bad news: dogs are significantly more sensitive to THC than humans, so even a small amount of cannabis can produce alarming symptoms that may need veterinary attention.
Why Dogs React So Strongly to THC
Dogs have a much higher density of cannabinoid receptors in their brains than humans do. These receptors are especially concentrated in areas that control balance, coordination, heart rate, and breathing. That’s why THC hits dogs harder and produces a different, more dangerous set of effects than it does in people. A dose that would barely register for a human can send a dog into a disoriented, uncoordinated state that lasts for hours.
What Symptoms to Expect
The most common signs of cannabis toxicity in dogs are urinary incontinence (your dog may dribble urine or have accidents), disorientation, a wobbly “drunken” walk, lethargy, heightened sensitivity to touch or sound, and a low heart rate. Your dog may seem startled by things that normally wouldn’t bother them, or they may become unusually still and unresponsive.
In more serious cases, dogs can experience tremors, vomiting, or a significant drop in body temperature. Severely affected dogs may become nearly comatose, with slow breathing, seizures, or a loss of their gag reflex. These severe signs are more likely in small dogs, puppies, or cases where the dog consumed a large amount or an edible product with a high THC concentration.
Symptoms typically appear within 30 to 90 minutes of ingestion, though edibles mixed with fats can sometimes take longer to kick in. Most dogs recover within 12 to 36 hours, though some may seem “off” for up to 72 hours depending on the dose and their size.
What to Do Right Away
Call your vet or an animal poison control hotline as soon as you realize what happened. Be honest about what your dog ate. Vets deal with cannabis cases regularly, especially in states where marijuana is legal, and they are not going to judge you or report you. What they need is accurate information so they can treat your dog properly.
Do not try to make your dog vomit at home. Unlike some other poisoning situations, inducing vomiting is not usually recommended for cannabis ingestion. Dogs affected by THC can lose coordination and normal reflexes quickly, which raises the risk of them inhaling vomit into their lungs. Let your vet decide whether any intervention is appropriate.
While you wait to get veterinary advice, keep your dog in a quiet, dimly lit room. Because THC can make them hypersensitive to noise and touch, reducing stimulation helps keep them calmer. Make sure they can’t fall off furniture or tumble down stairs, since their balance will be compromised.
What the Vet Will Do
Treatment for cannabis toxicity is mostly supportive. There’s no antidote for THC, so the vet’s job is to keep your dog safe and comfortable while the drug works its way out of their system. That usually means IV fluids to prevent dehydration, monitoring heart rate and breathing, and keeping your dog warm and stable. In some cases, vets use activated charcoal to reduce further absorption of THC from the gut, or a fat-based IV solution that helps the body process THC faster.
If your vet needs to confirm what your dog ingested, a standard over-the-counter urine drug test designed for humans actually works on dogs. A recent study in Frontiers in Veterinary Science found that a point-of-care THC urine test correctly identified all nine dogs with confirmed cannabis ingestion and returned negative results in every control animal. The test picks up THC breakdown products in dog urine even though dogs metabolize THC through a slightly different chemical pathway than humans.
Edibles Pose a Double Risk
A rolled joint is concerning, but edibles can be even more dangerous for two reasons. First, edibles typically contain a much higher concentration of THC than raw flower. Second, many edibles contain chocolate, xylitol (an artificial sweetener), or butter, all of which are independently toxic to dogs. If your dog ate a cannabis-infused brownie or gummy, the THC might not even be the most dangerous ingredient. Make sure to tell your vet exactly what form the cannabis was in.
Small Dogs and Large Doses Are Higher Risk
Most healthy adult dogs recover from cannabis ingestion without lasting effects. Deaths are rare but have been reported, typically involving very small dogs, very large doses, or products containing additional toxic ingredients. The combination of a depressed gag reflex, slow breathing, and low heart rate is what makes severe cases dangerous. A 5-pound Chihuahua eating a joint faces a very different situation than a 70-pound Labrador eating the same amount.
If your dog is very small, very young, elderly, or has an existing heart or respiratory condition, treat the situation as urgent and get to a vet immediately rather than waiting to see if symptoms develop.