Is THC / Marijuana toxic to dogs?

Marijuana affects receptors in the brain which alter normal neurotransmitter function, leading to neurological and physiological impairment.

There is no antidote, so care is supportive until the THC wears off. If your dog ate it within about the last hour and has no signs yet, the vet may make it vomit, although THC's anti-nausea effect can make this fail. Activated charcoal may be given, though sources disagree on whether mild cases need it. Mildly affected dogs that can walk and respond normally may be watched at home if the vet agrees. Sicker dogs stay in hospital for fluids, anti-nausea medicine, warming or cooling, and regular checks of heart rate, breathing, blood pressure and temperature, in a quiet, dim space. Specific problems get specific medicines, for example for a slow heart rate, agitation, tremors or seizures. Severe cases, such as concentrate ingestion or coma, may get an intravenous lipid emulsion, which helps soak up THC. If the edible contained chocolate, xylitol or raisins, the vet treats those too.

The outlook is good. Most cases are mild to moderate, and most dogs respond well to supportive care and recover fully within 1 to 3 days, with no lasting effects. Deaths are extremely rare. The serious cases are mostly linked to concentrates, THC butter and baked goods made with it, or very large doses.

• Edibles, the most common cause: brownies, cookies, gummies, candy, chocolate bars, chips and pot butter. They smell and taste like ordinary baked goods, which draws dogs to them.
• Other ingredients in edibles, such as chocolate, xylitol, raisins or a lot of fat. They add to the risk and need their own treatment.
• Dried plant or bud. Cats are more drawn to bud than to edibles, while dogs are more likely to eat edibles.
• Concentrates such as dabs, wax, shatter, budder and hash oil, which hold far more THC than the plant (solvent-extracted ones can be up to 80 to 90% THC), and oils, tinctures, capsules, topical balms and vape liquids.
• CBD or hemp products that contain more THC than the label says.
• Smoke, when a pet is in the same room as someone smoking.
• Things found outside or in the trash, such as discarded joint ends, human feces on walks or trails, and compost.

• Store all cannabis products, especially edibles, like any other medicine: in closed high cupboards or locked drawers where pets can't reach or sniff them out. Edibles smell like treats, and pets will go after cannabis candy, chips, chocolate and baked goods.
• Don't smoke or vape around pets. Keep them in a separate, well-ventilated room until the smoke has cleared.
• Throw joint ends and leftovers away where pets can't get them, and watch dogs on walks and trails, where discarded cannabis or human feces may be found.
• Talk to your vet before giving any CBD or hemp product to a pet. These products are poorly regulated, and some contain more THC than the label says.