If your dog eats marijuana, you’ll likely see symptoms within one to two hours, including loss of coordination, extreme drowsiness, and sometimes urinary incontinence. The good news: marijuana toxicity in dogs is rarely fatal, with the minimum lethal dose sitting at over 3 grams of THC per kilogram of body weight, roughly a thousand times the dose that triggers behavioral symptoms. But even non-lethal exposure can look alarming, and certain edible products carry additional dangers that can be more serious than the THC itself.
Why Dogs React So Strongly to THC
Dogs have far more cannabinoid receptors in critical parts of the brain than humans do. Specifically, their cerebellum, brain stem, and medulla oblongata are dense with these receptors. In humans, these areas carry very few. That matters because the brain stem and medulla control basic functions like breathing and heart rate, while the cerebellum handles coordination and balance.
This receptor concentration explains why dogs develop a distinctive symptom called “static ataxia,” where they stand still but sway or wobble, unable to keep their balance. It also explains why even a small amount of THC, well below what would affect a person, can produce dramatic neurological symptoms in a dog.
Symptoms to Watch For
Signs typically appear within one to two hours of ingestion, though it can take up to four hours if your dog hasn’t eaten recently. The most common symptoms include:
- Loss of coordination (stumbling, swaying while standing still)
- Extreme drowsiness or sedation
- Urinary incontinence (dribbling urine without seeming to notice)
- Hyperesthesia (exaggerated startle responses to touch or sound)
- Trembling or shaking
Your dog may seem confused, disoriented, or unusually sensitive to noise. Some dogs become very still and glassy-eyed. Others vocalize or seem anxious. The combination of severe sedation with occasional jerky reactions to stimuli is a hallmark pattern of THC ingestion in dogs, and it can look genuinely frightening even though the dog is typically not in danger of dying.
How Long It Lasts
Most dogs recover within one to three days. The body clears about 80% of ingested THC within five days, but noticeable symptoms in most cases fade well before that. Mildly affected dogs often return to normal within 12 to 24 hours. Dogs that consumed a larger amount, particularly through concentrated edibles, may seem “off” for closer to 72 hours.
The Real Danger: What Else Was in the Edible
The THC itself is rarely the biggest threat. What often makes marijuana edibles dangerous for dogs are the other ingredients. Chocolate edibles combine two toxins at once, since chocolate contains theobromine, which dogs metabolize very slowly. Edibles sweetened with xylitol (a sugar substitute also labeled as birch sugar) pose an even more urgent risk, as xylitol can cause a rapid, life-threatening drop in blood sugar and liver failure in dogs. Baked goods with raisins or macadamia nuts add further complications.
If your dog ate an edible rather than raw plant material, identifying the other ingredients is just as important as noting the THC content. This information helps the vet prioritize treatment.
Why You Shouldn’t Induce Vomiting at Home
THC’s sedating effects set in quickly, and a drowsy dog that vomits can aspirate, meaning the vomit enters the lungs instead of exiting the mouth. This creates a risk of aspiration pneumonia, which is more dangerous than the THC exposure itself. Dogs already showing any signs of sedation or loss of coordination should not be made to vomit, and activated charcoal carries the same aspiration risk.
THC also has natural anti-nausea properties, which can make it harder to induce vomiting in the first place. If you catch the ingestion within minutes, before any symptoms appear, a veterinarian may still attempt decontamination. But once symptoms are showing, that window has closed.
What Veterinary Treatment Looks Like
Treatment is primarily supportive. Your dog will typically receive IV fluids and medications to manage specific symptoms like nausea or agitation. The goal is to keep the dog comfortable, hydrated, and stable while its body processes the THC.
For more severe exposures, vets may use a specialized fat-based infusion given intravenously. Because THC dissolves in fat, this therapy helps the body trap and clear the compound more quickly. Most patients improve after a single treatment session, though some need a second round about 12 hours later. The prognosis with supportive care is good.
Why Drug Tests Often Fail in Dogs
If you’re unsure whether your dog actually consumed marijuana, don’t count on a human urine drug test to confirm it. These over-the-counter tests are designed to detect a specific THC byproduct that appears abundantly in human urine but barely shows up in dogs. Dogs metabolize THC differently, producing a more complex and variable mix of byproducts that human test strips simply aren’t designed to catch.
In one study, zero out of 25 suspected THC-positive dogs tested positive on a standard human drug screen. Another found just 1 positive result out of 21 suspected cases. Even when the same dogs’ blood was analyzed with advanced lab equipment, THC metabolites were clearly present. The human test just couldn’t detect them. Veterinarians typically diagnose THC toxicity based on symptoms and history rather than relying on these tests.
CBD Products Are a Different Story
Pure CBD is non-intoxicating and generally well tolerated in dogs, even in overdose amounts. At most, a large dose of a pure CBD product causes digestive upset. However, many CBD products marketed for pets or humans contain trace amounts of THC (legally up to 0.3%), and some have been found to contain unlabeled THC or synthetic cannabinoids due to poor quality control.
In one review of CBD exposure cases, 30% of dogs showed lethargy, 21% were uncoordinated, and about 6 to 7% had trembling or urinary incontinence. These symptoms are consistent with THC intoxication, not CBD, suggesting the products were contaminated. If your dog gets into a CBD product and shows symptoms beyond mild stomach upset, treat it like a THC exposure.