Marijuana poisoning is most common among dogs, though cats and rabbits have been known to partake. Symptoms of intoxication usually appear 30 minutes to several hours after ingestion, and may last for up to 96 hours. Classic presenting signs include incoordination, stupor, dilated pupils, low heart rate, and urinary incontinence. Treatment is primarily supportive once symptoms have started, but if caught early enough decontamination (inducing vomiting, activated charcoal administration) may be attempted.
The psychoactive ingredient in marijuana (delta 9-tetrahydrocannabinol, or THC) is rarely if ever lethal, so most cases recover with treatment. However, these same symptoms may be seen with other potentially fatal diseases or toxins. Sometimes owners are reluctant to admit that their pet might have eaten marijuana, but I can assure you, the vet doesn’t care. It will be much easier to diagnose and treat your pet if the vet has all the relevant information. Many emergency vets have urine test kits that check for drugs, and can make a diagnosis quickly, which can eliminate the need for more extensive testing.
So remember, an ounce of prevention… Keep all medications and potentially hazardous substances safely contained and out of reach. Because Chapter 2 of The Dangerous Book for Dogs is “Let’s Eat This, Too!”