Cops save puppy that ate shoplifting owner's heroin while left in truck

A 4-month-old puppy left alone in a Texas parking lot nearly died from a heroin overdose after eating his owners' stash, authorities said.

The tiny Chihuahua mix was found by police in a locked truck, lying on the passenger side's floorboard. He was barely breathing and seemingly comatose, Carrollton Police Department spokeswoman Jolene DeVito told Wednesday.

Read: After Living on the Streets, Beat-Up Pit Bull Won't Stop Cuddling with New Owner

His owners had left him inside their vehicle while they went inside a Home Depot to shoplift, she said.

"These people were switching price tags," DeVito said. "Then they went through the self-check-out line."

As they left the store, security guards took them into custody them after watching the pair remove a $499 tag and replace it with a $92 sticker, as well as trading a $345 tag for one reading $39.78, DeVito said.

As they were detained, "the woman told officers that 'Our dog is in the truck.' Sure enough, there he was, lethargic and almost comatose, on the passenger side," DeVito said.

The couple was identified by police as Nina Crawford, 38, and Thomas Romero, 46. They are being held at the Dallas County Jail on charges of theft and heroin possession following their Saturday arrest, according to online records.

It was not clear whether they had entered pleas.

The puppy, meanwhile, has made a miraculous recovery.

"He is doing fabulous. He is in great shape," veterinarian Stacie Fowler told "This little guy came in in really bad shape. He was barely breathing."

Animal care workers inserted an IV, gave him oxygen and administered a small dose of Narcan, a drug used to counter the effects of an opiate overdose.

He perked up pretty quickly, Fowler said.

Read: Woman Discovers Abandoned Puppy Inside Plastic Bag on Side of Road

"He's a wiggly, sweet little puppy," she said. "He deserves a sweet home."

He's now living at the city's Animal Services & Adoption Center, where he will be put up for adoption in the coming days.

And he's been given a new name.

"We're calling him Lucky," said employee Erica Martin.

Watch: Couple Is Shocked When Chocolate Lab Gives Birth to Green Puppy