My dog ate marijuana while out on a walk. Turns out, lots of dogs mistakenly ingest weed.

I took my dog Beau for a walk during a recent lunch break. It was trash day. He grazed on food rubbish. A half-eaten stale bread roll. A slice of American cheese stuck to the sidewalk.

We got back, and he settled into his dog bed at the foot of my desk. When my son came home from school, Beau didn’t get up to greet him as usual. We noticed his head wobbling and swaying. An hour later, he couldn’t pick his head up; his doggy lips were stuck to the hardwood floor in a smear of drool like two slugs.

I feared he ate rat poison near the pizza and sub shops on the White Horse Pike near my South Jersey home. I crouched eye level with Beau and thought, Is his left eye bulging slightly out of the socket? This was a 911 situation. I rushed him to Penn’s Mathew J. Ryan Veterinary Hospital emergency room in West Philadelphia.

The vet ordered the equivalent of a field sobriety test. He had Beau walk around so he could observe his gait.

His diagnosis: “Suspected marijuana ingestion.”

The vet, Charles Garneau-So, said Beau would be fine; the THC would clear his system within 24 hours.

“Marijuana toxicosis is typically relatively harmless, although unpleasant for the patient,” my hospital discharge paperwork read.

Wait, what? I thought. I detected a wry smile on the vet’s face. Feeling self-conscious, I swore to him that Beau got the drugs off the street.

Then, I crowdsourced for answers. Late one night, I turned to Facebook and asked friends whether this had ever happened to their dogs. It was surprisingly common.

Penn Vet’s hospital saw an uptick in cases after New Jersey legalized recreational marijuana in 2021, Garneau-So told me in an interview last week. Cases also soared in Pennsylvania after medical cannabis was legalized in 2016 and dispensaries opened statewide two years later, according to Tina Wismer, senior director of toxicology at the ASPCA’s Animal Poison Control Center.

“It’s not just your dog getting into trouble. It’s everybody’s dog,” Wismer said. “Dogs have no idea about serving size — ‘Oh, a whole pan of brownies. Yes, please!’”

The number of emergency calls for dogs that ingested marijuana has also jumped nationally. Wismer thinks it’s because cannabis, especially edibles, is increasingly ubiquitous and less stigmatized, so pet owners more readily admit the truth. (The dog-ate-my-homework antithesis).

Wismer had a theory about how Beau got high, which she prefaced by asking if I wanted to hear “the gross fun fact of the day.” Yes, please!

“Dogs that eat human stool from people who have ingested marijuana will become symptomatic,” Wismer said. “Your dog could have eaten poo.”

About 94% of THC will pass through the human body in stool, she said, pointing to a 2022 study in the Australian Veterinary Journal. (Hmmm, I did walk Beau down a weedy path to Newton Lake Park in Haddon Township — a nighttime party spot for local teens.)

Unlike cats, most dogs aren’t finicky. They’ll get into whatever is commonly around the house. During the pandemic, it was cleaning supplies.

Now, Wismer said, it’s weed gummies.

Carmen Maria Machado was preparing a Valentine’s Day dinner for her then-wife at their West Philadelphia home in 2020, when the couple’s dog, Rosie, knocked over a tray of bric-a-brac on the kitchen table with a tiny gift box from a friend that held “a single weed gummy.”

“Everything was scattered, and the box was open, and there was no more gummy,” Machado recalled. “I knew instantly what she had taken ... I called my then-wife, who was at work, and I was hysterically sobbing. I was totally freaking out.”

Val Howlett dashed out of work and jumped in a Lyft. The driver asked how Howlett’s day was going. “I’m a little stressed,” she explained. The driver commiserated. His dog once ate an entire tray of pot brownies. He assured her dog would be OK.

Once home, Howlett and Machado loaded Rosie, an 11-year-old “food-motivated” beagle mix, into their car. They sped to Penn’s Ryan Veterinary Hospital at 3900 Spruce St. At the time, Machado, author of the best-selling memoir In the Dream House, was an artist-in-residence at the University of Pennsylvania.

The vet technician took one look at Rosie and started laughing. “Are you going to pump her stomach?” Machado recalled asking. Too late, the tech surmised.

“Rosie was just sitting there so stoned, looking like she could see her ancestors,” Machado said.

The vet ordered IV fluids for Rosie to keep her hydrated and some anti-nausea medication to prevent vomiting.

Rosie’s home-care instructions, Machado said, sounded like advice you’d give to a human who consumed too much weed: Put her in a quiet room. Play soft music. Dim the lights. Let her ride it out. Vets call this “supportive care.”

“After I had gotten over the fact that I had poisoned my dog and thought she was gonna die, it was actually quite funny,” Machado said.

Back home with Rosie and a $600 vet bill, the couple wasn’t in a romantic mood. They ordered pizza that Valentine’s Day.

Dog owner Caroline Prasalowicz started our interview with, “The first time it happened... "

Prasalowicz lived in an apartment in Old City when her dog, Enzo, ingested marijuana at least three times.

“I could never quite figure out how he was getting it,” Prasalowicz said. The source, she suspects, was her neighborhood courtyard, where residents shared outdoor space and trash storage. She’s seen him eat dirt, rocks, sticks — and once a cicada that scratched his throat going down and landed them in the vet emergency room.

Enzo first ate cannabis in 2022 as a puppy. His head started bobbing. He couldn’t walk a straight line. He urinated on himself. Prasalowicz thought he had a brain tumor. She took a video to show the vet, then rushed him to Penn’s animal hospital.

The vet diagnosed a marijuana mishap.

Even when she watched him closely while out in the apartment courtyard or on walks, he still found weed. Once, she sought a second opinion. That vet reached the same conclusion: Enzo was a stoner.

Finally, Prasalowicz, a 28-year-old occupational therapist, moved to a house with a fenced-in backyard in Manayunk. He’s been sober ever since.

Scott Neabore, a vet who owns Neabore Veterinary Clinic in Haddonfield, said the most recent dog he treated for THC toxicity got it from an older person with a medical marijuana card for chronic pain. He also sees cases involving recreational cannabis.

Edibles. Vape cartridges. Joints. Neabore has treated dogs that have devoured all forms of cannabis. He has never known marijuana to cause death in dogs.

Some dog owners are sheepish at first. “We tell them, ‘Look, it’s not illegal. We’re not reporting anyone,’” Neabore said.

Other dog owners are truly confused, never suspecting their college-aged kid.

“At first they’re surprised and then they say they plan to go home to find someone to punish,” Neabore said.

» READ MORE: What caused a healthy dog's seizure-like symptoms? A medical mystery.

Susan Gobreski has three dogs — and three adult daughters.

About five years ago, her middle daughter came home from Smith College in Massachusetts, where recreational cannabis has been legal since 2016. The story of how her dog Max got stoned is a bit circuitous. “I can tell this more coherently if I had a glass of wine or two,” she told me on a recent Tuesday morning.

Her version starts like this: Gobreski’s dog Penny had torn a ligament and was on an anti-inflammatory medication for dogs. Her youngest daughter’s dog, Franklin, got ahold of the bottle and appeared to have gobbled all but one pill. Worried about organ failure, Gobreski took Franklin to the vet, where his system was flushed.

About 10 days later, Gobreski woke up and found Max stumbling around and twitching. She immediately thought it was Max — and not Franklin — that ate Penny’s pain pills. (Gobreski, a policy consultant who lives in Mount Airy, hadn’t witnessed the incident, only its aftermath.)

“Oh no, I saved the wrong dog,” Gobreski recalled thinking. “His kidneys or liver are now failing. Clearly, this is it. We’re going to have to say ‘goodbye’ to Max.”

Gobreski’s husband went downstairs to make coffee. He came back up with a wrapper and asked their middle daughter, “What’s this?”

She had brought a milk chocolate weed bar home from college.

Max inhaled the whole thing. “We had to put him on the couch and give him some Doritos,” Gobreski said.

A few weeks ago, it happened again. Only this time, Franklin ate the weed bar and “got very stoned.”

“He wasn’t giggling and listening to Pink Floyd,” she said. “But he went on a munching tear and got into a large bag of dark chocolate-covered pretzels. Then, he took a nap.”

It was the dark chocolate that had them in a panic. Chocolate contains an ingredient, theobromine, that’s toxic to dogs. Dark chocolate has the highest concentration of it.

Gobreski rushed Franklin to the vet. He’s fine now.

“It’s a cautionary tale for people who love dogs and like to ingest edibles,” Gobreski said.