It can take a couple of days for a dog to come down from a marijuana high. As with most marijuana-related things—illegality makes research hard to come by—there's not metric to measure how stoned a dog can get. (Medical marijuana for dogs has very low levels of THC.) If it comes down to weight alone, and a dog weighs 10 times less than a human, the marijuana could conceivably be 10 times stronger to the dog, as The New York Times pointed out. And the dog has no idea what's happening; he didn't sign up to get stoned, he just found something interesting to eat.
The symptoms of marijuana poisoning in dogs—"lethargy, wobbling gait, dribbling urine and saliva, overreacting to sound and light and movement"—aren't pleasant; they are not deadly, either. The A.S.P.C.A reports that all cannabis-related dog fatalities involve chocolate, which is essentially dog poison. But a dog is treated for cannabis exposure close to once a day in New York alone, and the number of incidences is increasing. As one vet told The Times, "We always used to joke about treating marijuana with fluids and Doritos and Pink Floyd. But we have had some serious intoxication—animals that become comatose, with extremely low blood pressure."
For the record, 95 percent of pet incidences with weed involve dogs, not cats, because dogs will eat anything at least once, just to see what's up.
