Pets
Can dogs have THC? What veterinary sources say about toxicity
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No. Veterinary toxicology references classify THC as a poison for dogs. The Merck Veterinary Manual reports mild signs at doses as low as 0.3 to 0.5 mg/kg and moderate signs above 2 to 3 mg/kg, with onset within 1 to 2 hours of ingestion (Merck). Death is extremely rare, but exposures have risen sharply with legal edibles.
THC is the one cannabinoid with a clear veterinary verdict. Every major reference classifies it as toxic to dogs, the dose thresholds are published, and the case counts have climbed with every state that legalized edibles. This page lays out the numbers.
How much THC affects a dog?
Very little, by human standards. The Merck Veterinary Manual states that dogs can develop mild clinical signs at THC doses as low as 0.3 to 0.5 mg/kg, with moderate signs above 2 to 3 mg/kg. For a 10 kg dog, that is roughly 3 to 5 mg for mild effects, which is less than a single standard adult edible. A 2021 review in Animals adds that smaller dogs are more susceptible and that the probable minimum lethal oral dose is greater than 3 g of plant material per kg of body weight, which is why fatalities are rare even as exposures are common.
Concentration makes modern products riskier than old ones. Merck lists marijuana plant at roughly 4 to 20 percent THC, hash oil at 20 to 50 percent and concentrates at up to 80 to 90 percent. A gummy or a butter-based baked good packs a meaningful dose into something a dog will eat on purpose. The two published canine deaths Merck cites both involved marijuana-butter baked goods.
What does THC exposure look like in a dog?
Onset after ingestion is within 1 to 2 hours, up to 4 hours in a fasted dog, and within minutes after inhalation. Merck's Pet Poison Helpline data from 2018 to 2023 show lethargy in 30 percent of cases, ataxia (loss of coordination) in 21 percent and vomiting in 15 percent, with urinary incontinence, trembling, slowed heart rate, dilated pupils and temperature changes also reported. The ASPCA Animal Poison Control Center lists prolonged depression, incoordination, sleepiness or excitation, excessive salivation, dilated pupils, low blood pressure, low body temperature and in severe cases coma, noting that death is rare.
The veterinary review describes the classic presentation as a lethargic or ataxic dog that is dribbling urine. Merck reports signs are self-limiting within 1 to 3 days, with recovery stretching to 5 days at higher doses, and summarizes THC exposure in both species as a "high morbidity rate but an extremely low mortality rate."
The controlled data agree. In a 2020 dose-escalation study, dogs given THC oil or a CBD/THC blend accounted for most of the moderate and severe adverse events, including ataxia, lethargy and low body temperature, and 3 dogs stopped dosing after severe events; the CBD-only group had none.
How common are exposures now?
Rising fast. The 2021 review in Animals reports a four-fold increase in canine cases in Colorado between 2005 and 2010 after legalization for human use, and a 765 percent increase in marijuana-ingestion calls to the ASPCA Animal Poison Control Center in 2019 compared with the same months a year earlier. Increases appeared in states where cannabis remained illegal as well. The exposure source is overwhelmingly human edibles left within reach, not products made for pets.
Hemp products are part of the picture. Federal law permits hemp to carry up to 0.3 percent delta-9 THC by dry weight, so a full-spectrum human tincture contains THC, and a large dog that drinks a bottle can reach the mild-sign threshold. Merck's dataset found THC-containing products made up 90 percent of cannabinoid cases in pets; a dog product should show ND for THC on its certificate of analysis.
What should an owner do after a suspected exposure?
Call a veterinarian or a poison control line immediately, before signs appear. The ASPCA Animal Poison Control Center is reachable 24 hours a day at (888) 426-4435; the ASPCA notes a consultation fee may apply. Bring the package if possible, because the THC content per piece and the presence of chocolate, xylitol or other ingredients change the plan. Do not induce vomiting at home in a dog that is already sedated or uncoordinated. Veterinary care is supportive: decontamination if early enough, fluids, temperature support and monitoring until the signs pass.
This page is general information, not personalized guidance.
General information, not personalized guidance.
Sources
- Toxicosis in Dogs and Cats From Tetrahydrocannabinol (THC) Merck Veterinary Manual (accessed 2026-10-13)
- Marijuana (Toxic and Non-Toxic Plants) ASPCA Animal Poison Control Center (accessed 2026-10-13)
- Cannabis, Cannabidiol Oils and Tetrahydrocannabinol: What Do Veterinarians Need to Know? Animals (Basel), via PubMed Central (accessed 2026-10-13)
- Preliminary Investigation of the Safety of Escalating Cannabinoid Doses in Healthy Dogs Frontiers in Veterinary Science (accessed 2026-10-13)
- 7 U.S. Code 1639o - Definitions Cornell Law School, Legal Information Institute (accessed 2026-10-13)
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