Of all the things Andy Healy worried could poison her dogs, cannabis wasn’t on the radar.

That changed, though, after what was supposed to be a fun 15-mile hike in the woods ended with an evacuation and a trip to an emergency animal hospital.

Healy set out Oct. 29 on the Siouxon Creek Trail in the Gifford Pinchot National Forest with her friends Laura Stockton and Rick Blevins and her two 5-year-old border collies, Fen and Jil.

Nearly 13 miles into the hike, Fen began to stumble and weave. She sat down and was unable to get back up. She lost the ability to move her front legs; then, she couldn’t move her back legs. When Healy reached out to touch her dog, Fen flinched. Then, her eyes glazed over.

Immediately, Healy knew her dog had been poisoned. Based on the symptoms, Healy suspected cannabis poisoning. Healy, a trauma nurse, had researched the topic after recreational marijuana use became legal in Washington, but she never imagined Fen would come across cannabis in the middle of the woods.

But Dr. Heather Poncelow, a veterinarian at Columbia River Veterinary Specialists in Vancouver, said it’s more common than people probably think.

Poncelow and her colleagues frequently see THC toxicity in dogs. And while it’s more common to see poisoning in dogs that got into cannabis in their home, exposure happens in parks and other public places “relatively frequently,” Poncelow said.

The good news, though, is THC toxicity is rarely fatal.

“It’s extremely uncommon, or rare, that a pet would die from THC toxicity,” Poncelow said.

Fortunately, Fen has fully recovered, but not without leaving Healy with a harrowing story to tell.

Rescuing Fen

Healy often hikes alone and has thought about how she would evacuate one of her 35-pound dogs if something were to happen. But a recent hip replacement surgery, from which Healy is still recovering and building endurance, would have hampered those efforts.

“It would’ve been all I could do to carry her out,” Healy said of Fen.

Luckily for Healy, her hiking partners are also her teammates with Silver Star Search and Rescue out of Washougal. The trio used trekking poles, a tarp and some line in their packs — along with tree branches — to create a litter to carry Fen the 2 1/2 miles back to the car.

It was dusk by the time they reached the trailhead, and Fen was unresponsive. Her breathing was shallow — just six breaths per minute — and her body temperature was dropping.

Healy made the nearly two-hour drive to Columbia River Veterinary Specialists, where veterinarians treated Fen for hypothermia, warmed her up and monitored her breathing.

“They assured me that this looks like classic marijuana poisoning,” Healy said.

A few hours later, Healy took Fen back to their Ridgefield home. Another 10 hours would pass before Fen could stand and walk and another day before she was running and playing.

Healy suspects Fen came across a cannabis edible while the group stopped at a vacant campsite to rest and eat a snack. Fen and Jil were exploring the area, and Healy admits she was distracted while talking to her companions.

Healy doesn’t think anyone left the edible intentionally. More likely, she said, a camper dropped it without realizing.

The troubling thing with cannabis edibles, Poncelow said, is many of them are meant to provide multiple doses. A dog, however, will eat the whole thing.

“When they’re getting edibles, they’re getting exposed to more THC than if they got a hold of a half-smoked joint,” she said.

Columbia River Veterinary Specialists see about one to three cases of THC toxicity each week. While that hasn’t changed since marijuana became legalized, people do seem to be more cavalier and don’t secure their cannabis from pets and children, Poncelow said.

Healy hopes Fen’s experience serves as a warning and a reminder about the danger marijuana poses when it gets in the wrong hands — or paws.

“People need to think of it as leaving a loaded gun around a kid,” she said. “It’s not harmless.”