Yes, weed is toxic to dogs. THC, the psychoactive compound in marijuana, affects dogs much more intensely than humans, and even small amounts can cause symptoms that require veterinary care. Deaths are extremely rare, but the experience is distressing for the animal and can lead to serious complications in some cases. Calls to the Pet Poison Helpline about marijuana in dogs increased 430% between 2019 and 2023.
How Much It Takes to Cause Problems
Dogs can develop mild symptoms from THC doses as low as 0.3 to 0.5 mg per kilogram of body weight. To put that in perspective, a single cannabis gummy could easily contain 5 to 10 mg of THC, which is enough to affect a medium-sized dog. At doses above 2 to 3 mg/kg, symptoms become moderate to severe.
The lethal dose is extremely high, exceeding 3 to 9 grams of THC-dominant plant material per kilogram of body weight. No confirmed median lethal dose exists, and fatal outcomes are exceptionally rare. When deaths have occurred, they appear to result from complications like aspiration (inhaling vomit into the lungs) rather than THC itself.
What THC Toxicity Looks Like
The classic presentation is a dog that looks depressed or wobbly and is dribbling urine. Symptoms typically begin within about 75 minutes of ingestion, though they can appear as early as 30 minutes or as late as 12 hours afterward. Most dogs show signs within 4 hours.
You may notice your dog stumbling, seeming disoriented, or reacting slowly to sounds and touch. Urinary incontinence is common and often one of the first things owners notice. Changes in heart rate, dilated pupils, tremors, and excessive drooling can also occur. Some dogs become agitated; others become unusually sedated. In severe cases, dogs can become unresponsive or comatose.
Edibles Are the Biggest Risk
Most veterinary cases of cannabis toxicity come from dogs eating marijuana edibles, not from secondhand smoke or raw plant material. Edibles are attractive to dogs because they’re often flavored like treats, and they tend to contain concentrated doses of THC.
The bigger concern with edibles is what else is in them. Many contain chocolate, xylitol (an artificial sweetener used in sugar-free products), or raisins. Each of these is independently toxic to dogs. A chocolate cannabis brownie, for example, creates two separate poisoning events at once, which makes the situation significantly more dangerous and harder to treat. Smaller dogs face higher risk because it takes less of any toxin to affect them.
What Happens at the Vet
If your dog ate marijuana within the last 30 minutes, a veterinarian may try to induce vomiting, though THC has anti-nausea properties that can make this difficult. Treatment is primarily supportive: keeping the dog warm, hydrated, and monitored until the THC works its way out of the system. In severe cases where a dog’s blood pressure drops dangerously low or the animal becomes comatose, vets can use intravenous fat-based fluids that help absorb the THC more quickly because THC dissolves in fat.
A study of 223 cases found that the median hospital stay was 24 hours, with a range of 6 to 72 hours. All dogs who returned for follow-up had fully recovered. So while the experience can be frightening, the prognosis is generally good with proper veterinary support.
Vets can confirm marijuana exposure using a simple urine test. These point-of-care tests, originally designed for humans, have been shown to reliably detect THC metabolites in dogs despite differences in how the two species process the compound. If your dog gets into your stash, be honest with your vet. They need accurate information to provide the right care, and they’re not going to report you.
CBD Is a Different Story, but Still Complicated
CBD and THC are different compounds with very different effects on dogs. CBD does not produce the intoxication or toxicity that THC does, and early research suggests it may have therapeutic value for conditions like epilepsy and osteoarthritis pain in dogs. However, no CBD product has gone through FDA approval for animal use.
The practical problem is quality control. Lab analyses have found that a substantial portion of CBD products on the market are labeled inaccurately, both in terms of what’s in them and how much. Some products marketed as CBD-only contain enough THC to cause problems. The FDA has issued multiple warning letters to companies selling CBD products illegally and has stated it cannot confirm that CBD products meet safety standards for animal food. If you’re considering CBD for your dog, work with a veterinarian who can help you navigate product selection rather than buying something off the shelf.
Keeping Your Dog Safe
Dogs don’t know the difference between an edible and a regular treat, and they’ll eat both with equal enthusiasm. Store all cannabis products, including flower, edibles, tinctures, and vape cartridges, in sealed containers in places your dog can’t reach. Be especially careful with edibles left on low tables, in bags on the floor, or in coat pockets at dog-nose height.
If you smoke or vape indoors, be aware that dogs in enclosed spaces are exposed to secondhand smoke, though ingestion remains the far more common and dangerous route. Outdoors, discarded joints and roaches on sidewalks or in parks are a real hazard for dogs that scavenge during walks. If you see your dog pick something up, check what it was before they swallow it.