THC stays in a dog’s system for up to 5 days, though most of the compound clears sooner than that. Dogs excrete about 80% of THC within 5 days of exposure, with the majority leaving through feces (85%) and a smaller portion through urine (15%). The visible effects, the part most owners are worried about, typically resolve within 1 to 3 days.
How Dogs Process THC Differently
Dogs metabolize THC through a different pathway than humans, and they’re far more sensitive to it. THC is highly fat-soluble, meaning it gets absorbed into fatty tissue after ingestion and then slowly releases back into the bloodstream over time. This is why a dog can still seem “off” for a day or two even after the worst symptoms have passed.
After a single exposure, THC is measurable in a dog’s blood for at least 24 hours. With repeated or larger exposures, THC and its breakdown products can linger in the blood for even longer. In one pharmacokinetic study published in Frontiers in Veterinary Science, THC and its metabolites were still detectable in dogs’ blood 12 hours after dosing on the 20th consecutive day of oral administration, suggesting the compound accumulates with repeated exposure.
The fecal elimination route is worth noting because it means THC recirculates through the liver and intestines before leaving the body. Dogs that eat their own stool or another dog’s stool during this window could theoretically re-expose themselves to small amounts of THC metabolites.
When Symptoms Start and How Long They Last
Signs of THC exposure in dogs typically appear within 1 to 2 hours of ingestion. If your dog hasn’t eaten recently, onset can take up to 4 hours, which sometimes tricks owners into thinking their dog is fine before symptoms suddenly appear. Common signs include wobbliness, dilated pupils, dribbling urine, an exaggerated startle response, and lethargy. Some dogs become agitated instead of sedated.
Most dogs recover fully within one to two days. In more severe cases, where a dog ate a large amount of an edible or a concentrated product, symptoms can persist for up to 72 hours. The good news is that the prognosis is generally excellent with supportive care, and most dogs return to completely normal behavior once the THC clears.
What Affects How Quickly THC Clears
Several factors influence how long THC lingers in your dog’s body:
- Amount ingested. A dog that licked a small amount of cannabis butter will clear THC much faster than one that ate an entire bag of edibles. Higher doses saturate more fat tissue and take longer to fully eliminate.
- Body fat percentage. Because THC binds to fat, dogs with more body fat may store the compound longer. An overweight lab will likely retain THC longer than a lean greyhound.
- Type of product. Edibles, oils, and butter contain THC that’s already been processed into a form the gut absorbs efficiently. Flower or plant material may pass through more quickly because the THC isn’t as bioavailable. Concentrated products like vape cartridge liquid or distillate deliver a much higher dose per gram.
- Whether the dog’s stomach was full. Dogs that ate on an empty stomach tend to show signs sooner but may also process the THC faster. Fasted dogs can take up to 4 hours for symptoms to appear, but this delay is about absorption timing, not elimination speed.
The 5-Day Elimination Window
Even after your dog looks and acts completely normal, trace amounts of THC and its metabolites remain in the body. The 80%-in-5-days figure from veterinary literature means roughly 20% of the original THC load is still being processed after nearly a week. For a mild exposure this residual amount is negligible, but it helps explain why some dogs seem slightly subdued or have soft stool for a few days after they otherwise appear recovered.
Full elimination, meaning zero detectable THC in the body, likely takes somewhere beyond 5 days for a significant exposure. Veterinary research hasn’t pinpointed the exact “100% clear” timeline because it varies so much by dose and individual dog, but for practical purposes, a dog that looks normal, is eating well, and is behaving like themselves is functionally recovered even if trace metabolites remain.
What Recovery Looks Like
Veterinary treatment for THC exposure is supportive, not curative. There’s no antidote that neutralizes THC. Instead, the focus is on keeping your dog safe and comfortable while their body does the work of processing and eliminating the compound. This typically means keeping them in a quiet, warm environment, preventing them from injuring themselves if they’re uncoordinated, and ensuring they stay hydrated.
Dogs that are vomiting, extremely lethargic, or unable to walk generally benefit from veterinary monitoring. If you bring your dog to the vet, expect them to be observed for several hours and possibly kept overnight in severe cases. Be honest with your vet about what your dog ate and how much. Veterinarians aren’t required to report THC exposure, and knowing the substance helps them rule out other toxins that could be more dangerous and require different treatment.
Most dogs bounce back to their normal selves within 24 to 48 hours. By day 3, even dogs with severe exposures are typically eating, walking, and behaving normally. The lingering metabolites after that point don’t produce any noticeable effects.