Since recreational marijuana is now legal in Oregon, it’s prudent to talk about toxicity for dogs since they’ll be the first to nab any unattended stashes. The psychoactive ingredient in marijuana is delta 9-tetrahydrocannabinol (a.k.a. THC). Regular marijuana is usually 1-8% THC. Hashish (made from the flowering tops of the plant and their resins) is up to 10% THC.
Second-hand cannabis smoke is not considered a hazard for dogs. Ingested cannabis can be. Cannabis made into foods is especially attractive to dogs, and when infused into butter or oil is even more potently absorbed into the bloodstream. Since THC is stored in the body’s fat deposits, the effects of marijuana can last for days.
Signs of marjuana ingestion begin after roughly 30 minutes (range 5 minutes to 96 hours) and can include incoordination, listlessness, dilated pupils, slow heart rate, low blood pressure, and urinary incontinence. There have been two known deaths in dogs from eating baked goods made with medical grade THC butter. Since signs can look like those from other recreational drugs it’s important to inform the veterinarian of the drug type, potency, and amount ingested. If edibles containing chocolate, macadamia nuts, raisins, or the sweetener xylitol are ingested that information needs to be relayed since those are toxic too.
Treatment may include feeding activated charcoal (used to trap and eliminate toxins in general), intravenous fluids, warming, and other interventions as needed. The induction of vomiting is not recommended unless within the first 30 minutes of ingestion since the nausea-control properties of THC interfere, and in sedated patients vomiting may result in aspiration pneumonia.
Since recreational marijuana was legalized in Colorado, their human and veterinary hospitals have seen a significant increase in the number of children and dogs presenting with THC toxicity. We will soon be seeing the same trends in Oregon. If you think your dog may have ingested marijuana, please seek veterinary assistance as soon as possible.
***A note about medicinal marijuana for dogs: Veterinarians in the U.S. cannot dispense or write prescriptions for medicinal marijuana. And while oils extracted from hemp (containing the medicinally bioactive compounds with substantially less THC) are available on the internet, very little research exists regarding their effects in animals, and dosages for dogs have not been studied. We cannot advise on the use of any form of cannabis for your pet.