It was midnight and Sara Aglietti’s mixed breed terrier Pickle could not stand or walk. Several hours earlier, Pickle became unusually lethargic. Her head bobbed back and forth, and her heavy panting eventually transitioned to slow breaths.
“That really scared me,” said Aglietti, of Louisville, who drove 8-year-old Pickle to the emergency veterinary hospital in Boulder.
“When I took her into the ER, they took one look at her and said she ate marijuana,” Aglietti said of the incident two years ago.
Aglietti suspects Pickle ate a marijuana edible left behind on the Dry Creek Trail in Boulder County earlier that day. Veterinarians kept Pickle at the hospital until her vitals returned to normal, including her heart rate. And Pickle made a full recovery at home over the next few days.
Stories like Pickle’s are not uncommon in Colorado, which ranks among the top 10 states for highest percentage of marijuana use in the past year by adults. Colorado legalized marijuana for medicine in 2000 and for recreation in 2012, the first to do so alongside Washington state.
Stacy Meola, associate medical director at Wheat Ridge Animal Hospital, was one of the first to report an uptick in marijuana intoxication in dogs in 2012 and has been tracking it ever since.
“The numbers have definitely gone up over the last 15 years,” said Meola of canine marijuana intoxication cases in Colorado, adding that nationally the numbers have surged too.
In 2024, the American Society for the Prevention of Cruelty to Animals Poison Control hotlines received 6,333 calls related to accidental marijuana ingestion in animals, up from 1,768 such calls in 2018. Beginning in 2019, there was a jump in calls, and during the first few months of that year, hotlines reported a 756% increase from a previous 10-year period.
“With more states legalizing marijuana, this trend is likely to continue,” said Tina Wismer, senior director of toxicology at ASPCA Poison Control, in an email. Medicinal use of marijuana is legal in 48 states and Washington, DC, and recreational use of marijuana is legal in roughly half of states.
Tetrahydrocannabinol, or THC, the psychoactive compound in marijuana, is toxic for dogs. The most common signs of marijuana intoxication are stumbling and “walking like they’re drunk,” Meola said. A majority of dogs just sit there swaying, not really paying attention, and dribbling urine, she added.
“I always joke that if 50% of humans peed all over themselves every time they did pot, it probably wouldn’t be as popular of a recreational drug,” Meola said.
Unbeknownst to their owners, dogs, like Pickle, eat marijuana edibles or partially burned joints carelessly left behind at a park or on a trailhead, or counter surf their owners’ supply left out at home. Meola has seen a couple of dogs high from inhalation, but those are the minority.
“Edibles are always dogs’ favorite just like they are with people because they taste good,” she said.
Aglietti suspects Pickle ate an edible when they were hiking off-leash as part of Boulder County’s Voice and Sight Tag Program. Pickle’s accidental high didn’t surprise Aglietti who has lived in Colorado for 10 years. “People drop things from their pockets, right? They pull out their poop bags and a candy falls out.”
Marijuana’s increasing prevalence and THC concentration is a double whammy for pets. Legalization and decreasing stigma mean more people leave marijuana-based products out in their homes, said Wismer. “The concentration of THC in these products has also significantly increased, affecting the severity of toxicity in animals,” she said.
Most dogs recover completely on their own at home from marijuana intoxication, Meola said, but the first several hours can be scary for owners because dogs appear to suffer from a neurological disorder. Besides urinary incontinence, stupor and difficulty with balance, other symptoms include tremors, drooling, low heart rate and body temperature, hyperactivity and glassy eyes and dilated pupils.
Rather than trying to hide it, people in Colorado are usually open and honest about their dogs’ potential access to marijuana in the home, Meola said, and are relieved that the cause is not life threatening or requiring an expensive magnetic resonance imaging, or MRI.
Smaller dogs that are more severely affected may need an intralipid treatment, which involves putting fat into their veins that binds to THC and is later excreted.
Other new treatments in testing
New treatments are in the pipeline. Last year, Meola and her colleagues published a small pilot study of a drug called Flumazenil, used to treat overdoses in humans. They treated 17 dogs with marijuana intoxication with Flumazenil, which showed promise in helping mitigate symptoms and reduced intoxication time, especially in severe cases.
In another case study, Florida veterinarians were the first to use cannabidiol, or CBD, to treat marijuana intoxication by placing a CBD-infused sheet on the gums of six dogs. CBD is thought to inhibit metabolism of THC and resulted in improved clinical symptoms.
“The vast majority of dogs are going to be perfectly fine in 24 hours and not need hospitalization, but we certainly see some severe side effects that may require hospitalization,” Meola said.
Edibles can contain other toxic ingredients other than THC such as chocolate and xylitol, Wismer said. Chocolate can increase heart rate, hyperactivity and seizures, and is the most problematic for a small dog that eats a large amount of THC-laced chocolate. Xylitol can cause low blood sugar and damage dogs’ livers.
Though THC exposures dropped last year, Wismer said hallucinogenic mushroom exposures, such as psilocybin and muscarine, are rising in pets. Colorado is one of two states that has legalized psilocybin for recreational use.
Pickle was not Aglietti’s first dog to get stoned. Scout, a shepherd mix from Mexico, accidentally ingested marijuana, but because he weighed 35 pounds, he recovered more quickly than Pickle, who is under 20 pounds.
Dogs like Pickle and Scout are not the only accidental weed eaters. Cats can also suffer marijuana intoxication, but they’re more attracted to the bud form, rather than edibles, Wismer said.
Besides looking out for roaches or edibles, owners should be vigilant on walks about dogs eating human feces because of the potential for it containing THC. Australian veterinarians have described 15 cases where dogs had eaten human feces with high THC from parks, beaches, campsites and walking trails.
Being responsible by treating marijuana just like any other drug you wouldn’t want your kids or pets to get into is the key to reducing exposure for animals, Meola said. But our state is a perfect storm of conditions for canine marijuana intoxication. “There’s a lot of pot in Colorado and a lot of dogs.”
