Dr. Tim Hackett, director of Colorado State University’s James Voss Veterinary Teaching Hospital, said such cases are more common in places where marijuana is legal for medical use — 21 states and the District of Columbia — and in Colorado and Washington state, which have legalized recreational use.
But it also occurs in states where any use of marijuana is illegal, he said.
“There’s a significant correlation between the number of people using marijuana freely now and dogs being treated for a high,” he said.