3-month-old Labrador puppy revived after ingesting opioid during walk

— -- A Massachusetts dog has fully recovered from a life-threatening opioid overdose, her owner said.

Zoey, a 3-month-old Labrador, fell ill last week after chewing on a cigarette box she found last week on the ground during her morning walk.

The incident occurred at around 7:30 a.m. last Friday, Peter Thibault, 48, her owner, said.

"She's a puppy so you really don't walk a puppy. They kind of go where they want to go. They sniff things out every couple of feet," Thibault of Andover, Massachusetts, told ABC News.

"She went for it and she got it in her mouth; the box and the tinfoil wrapper the cigarettes come in,” which apparently contained the drug.

He went on, "I quickly removed it from her mouth and I didn't think anything of it. It appeared that it was a completely empty box of cigarettes that someone drove by and then threw out the window."

Soon after, Thibault said, Zoey collapsed.

"I tried to get her on her feet and I realized something wasn't quite right," he recalled. "I didn't think it was a life-or-death situation. I Facetimed with my wife and at that time [Zoey's] eyes rolled in the back of her head and her tongue was hanging out. It looked like she was going to die."

Thibault brought Zoey to Bulger Veterinary Hospital in North Andover where veterinarians determined she had ingested fentanyl, a powerful synthetic opioid that is 50 to 100 times more potent than morphine, according to the National Institute on Drug Abuse.

The puppy was revived with naloxone, the drug that works to reverse the effects of an opioid overdose, Bulger Veterinary Hospital wrote in a statement on its website.

"She was weak, recumbent, and had a low heart rate," according to the statement. "Due to these signs as well as the sudden onset in an otherwise healthy puppy, and the history of encountering the trash just before the collapse, a toxin was suspected."

After 12 hours of monitoring and care, Thibault said, Zoey was released.

"She's a regular puppy now chewing on everything, wrecking the house," he said. "The vets did a really good job. Bulger was just a phenomenal hospital and the dog responded quickly to the anti-opioid medication."

Later, Thibault said, he called the Andover Police Department and reported the incident.

Police did not immediately respond to ABC News' request for comment.

Now, Thibault said he hopes Zoey's story brings awareness to the opioid crisis.

"I never, ever thought something like this could ever occur to me, my pet, my family,” he said. “It's just such an eye-opener that the opioid epidemic is real and it crosses every line that it can.”