VANCOUVER -- A Vancouver woman is pleading with pot smokers to properly dispose of their roaches after her puppy suffered the toxic effects of THC twice in less than a year.

Gemma Fletcher said the latest incident happened Wednesday while she was walking 13-month-old Maddie in Charleston Park, where the Boston terrier sniffed out someone's discarded roach and started eating it.

Though Fletcher managed to get Maddie to spit part of the roach out, it was apparently too late. The dog started acting strangely hours later.

"She was trembling and not able to stand, she was very sensitive to sounds and touch – just terrified," Fletcher said.

She recognized the symptoms as THC toxicity immediately, as it had only been a matter of months since the last time Maddie ingested pot that had apparently been tossed away by a stranger.

The puppy was only four months old when it happened the first time, and had to be taken to an emergency veterinary hospital. Fletcher said beyond being frightened and uncomfortable, Maddie also had "complete incontinence."

"That wasn't a problem this time, fortunately," she added.

Fletcher said she's seen an increase in people smoking cannabis outside in her Fairview neighbourhood since Canada legalized recreational use. She told CTV News she shared her story in the hopes that smokers will be more careful, and clean up after themselves instead of throwing roaches on the ground.

"What I want is to bring some awareness that even a little roach that people litter can be very toxic (to dogs)," she said. "People don't realize that. They think it's harmless because the effects aren't serious for humans."

According to the B.C. SPCA, THC, the psychoactive component of pot, can cause "seizures, coma and even death" in pets. And the Canadian Veterinary Medical Association has reported a "precipitous increase" in TCH-related incidents since legalization.

Fletcher said she's a conscientious dog owner, but it's impossible to monitor every single thing Maddie smells or interacts with while they're on walks, particularly when they're at the off-leash area of Charleston.

"Dogs are just picking up sticks and sniffing things and eating things all the time," she said. "There's nothing I can do except leave her in plastic bubble wrap or put some kind of face mask on her."