A dog owner in Prince George, B.C., says she was physically ill after learning her family pet had been shot in the head multiple times with a nail gun.

The German shepherd, Kuma, survived the injuries, and the BC SPCA has launched a cruelty investigation in hopes of catching the perpetrator.

The dog went missing on June 24 and was found four days later wandering the highway in Hixon, about 60 kilometres away.

It was turned in to the North Cariboo BC SPCA branch. The dog managed to walk into the shelter on its own, but upon further inspection staff noticed there were puncture wounds on the animal's skull.

Although it was initially believed he was shot with a pellet gun, a veterinary x-ray revealed something more sinister: three nails, each measuring three inches long, were lodged into its skull. It's believed the dog was shot by a nail gun.

"If this makes you sick, I actually threw up. Someone must know something about this," owner Maureen Yeo wrote in a Facebook post.

BC SPCA branch manager Jamie Walsh told CTV News the dog is "very, very lucky" to have survived such a horrific injury, and they were able to rush it to a vet right away for surgery.

"We've never seen anything like this," said Walsh. "It's intentional – things like this don't happen by accident."

The dog has had a few seizures since undergoing surgery but is expected to survive. The dog is eating and drinking and wagging his tail, reports Yeo.

The animal welfare agency is appealing for the public to come forward with any information about the case.

So is Yeo, who believes someone must know something about what happened to Kuma.

"Please come forward with any information you may have before whoever did this gets a hold of another dog," she said.

Anyone with information is asked to call the BC SPCA cruelty hotline at 1-855-622-7722.