Dr. Timothy Hackett is a professor of veterinary emergency medicine, the author of a textbook on animal emergency procedures, and the director of the Colorado State University Veterinary Teaching Hospital. When it comes to sick dogs, he’s seen it all.
But there’s one type of case he’s been seeing more and more frequently since voters in Colorado legalized marijuana: dogs sick from eating marijuana-infused food — like cookies and candy — that humans accidentally left out.
“With the increase in all these recreational products, we saw the number of marijuana intoxications go way up — several dogs a week here,” Hackett, 55, said, referring to his hospital. “It’s all about the fact that edibles are tasty. A dog is not going to stop at a single cookie, but just keep eating until they’re all gone.”
Which is to say the implications of a November ballot question to legalize marijuana in Massachusetts could extend to your family’s canine.
Dogs almost never die from eating marijuana products, vets say, but they do get sick.
“They’re stumbling, falling over on themselves,” said Dr. Stacy D. Meola, an emergency medicine vet at Colorado’s Wheat Ridge Animal Hospital, who helped conduct a study on dogs and marijuana toxicosis.
“About 50 percent of dogs urinate on themselves, just dribbling urine,” she said. “I often joke if that was a human response, using marijuana wouldn’t be quite as popular for people.”
Dr. Lee Herold is chief medical officer of DoveLewis Emergency Animal Hospital in Portland, Ore., one of four states where recreational marijuana is legal. She compared the number of patients suffering from marijuana toxicosis between October 2014 and October 2015, and October 2015 and this month.
“We definitely have seen an increase,” she said, pegging the number at 75 more dogs in the past 12 months. That’s a more than 60 percent increase as legal marijuana has become more and more accessible, Herold said. She said the vast majority of exposures are dogs accidentally ingesting marijuana, rather than a human giving it to them on purpose.
Although the science of dogs and marijuana remains in its infancy, vets say dogs often end up high for much longer than humans.
Hackett said dogs “metabolize marijuana differently than people.” He’s had owners get high with their dogs, then panic and bring them to the hospital the next morning when the humans have sobered up and their pooches are still stoned.
Depending on when and how much marijuana dogs are suspected of ingesting, treatment sometimes includes inducing vomiting and giving the animals activated charcoal to help soak up THC, the main psychoactive chemical in marijuana, that vets say makes dogs sick.
The specter of more dogs sick from pot worries some local vets, such as Dr. Kiko Bracker, director of emergency and critical care at Angell Animal Medical Center in Jamaica Plain.
Massachusetts voters decriminalized the possession of marijuana in 2008 and legalized it for medical use in 2012. Bracker said in recent years his hospital has seen more cases of dogs suspected of ingesting marijuana, and he indicated he expected a further uptick in such cases if voters legalize it for recreational use.
But he emphasized that dogs don’t find their way to pot alone and, with or without legalization, marijuana users have a responsibility to “make sure it’s out of the way of kids and dogs.”
And, Bracker added, “if there is one silver lining to legalization, it’s that marijuana is not such a dangerous toxin to dogs. To my memory, I’ve seen one or two dogs that were very, very sick from marijuana, near comatose, for a few days, but that’s really the exception, not the rule.”
(Marijuana infused products tend to appeal a lot more to dogs than cats, vets say.)
There’s another twist to legalization for pets — marijuana-infused products meant to make them feel better. Manufacturers say their products use one of marijuana’s nonpsychoactive substances, cannabidiol or CBD, to help dogs and cats that are suffering. That’s different from THC, the main substance that gets people high.
For example a brand called Therabis, based in Colorado and owned by a major make of edible marijuana products for humans, sells “hemp-based products to help your dog with itching, anxiety and joint mobility.”
Its website says one such product, Calm and Quiet, “uses naturally occurring cannabinoids to quickly reduce anxiety and help dogs keep their cool.”
The Food and Drug Administration has said it is gathering information on marijuana products marketed for pets but has not evaluated them. So it’s no surprise that several vets expressed caution on such products, which are also aimed at cats.
“We don’t prescribe marijuana products,” Bracker said, pointing to the dearth of data on their effects.
Meola, one of the vets in Colorado, said that while there may be some healing components in marijuana plants, there are not yet any scientific studies looking at the ameliorative impact of such products on animals. “Without studies proving their efficacy, and having the blessing from the FDA, I would not recommend them,” she said.
Joe Hodas, a spokesman for Dixie Brands Inc., which owns Therabis, said he understands if a vet requires a clinical trial before recommending a product. But, he continued, the truth is “this is a very nascent industry. There isn’t a deep body of clinical work to support it yet. We have field trials. We have happy customers. And we believe we are helping our country’s pets.”
Hodas said Therabis is in the midst of a clinical trial with the University of Pennsylvania, “but until we have those results back, we will have to stick with wagging tails and slobbery kisses for our feedback.”
Opponents in Massachusetts sometimes refer to the perils of legalization for pets, though it is not one of their main arguments against making the drug legal.
Jim Borghesani, communications director of YES on 4, which backs legalization, brushed off talk of danger to pets as fear mongering.
“We know that our prohibitionist opponents are using the pet angle as a scare tactic, and we’re aware of no studies that support their alarmist rhetoric,” he said in an e-mail. “Every owner should observe the basic responsibility of keeping any potentially harmful item away from their pets.”
Vets in other states offered something of a public service announcement for the many pet owners across this state if voters legalize marijuana in November.
Said Hackett: “Protect your stash! Dogs will be attracted to it and will eat the whole bag of brownies.”Joshua Miller can be reached at firstname.lastname@example.org. Follow him on Twitter @jm_bos and subscribe to his weekday e-mail update on politics at bostonglobe.com/politicalhappyhour