Nanook, who was found with a gunshot wound in a hind leg, is available for adoption. (Cochrane and Area Humane Society)

A puppy that narrowly avoided amputation after he was shot in the upper hind leg may have to wear a special boot for the rest of his life.

Nanook, a two-year-old Collie-German shepherd mix, limped home, west of Calgary, in February where his owners discovered the gunshot wound, said Cheryl Wallach, marketing coordinator for the Cochrane and Area Humane Society.

"They knew they weren't able to provide treatment for the dog so ended up having to surrender him," she said on Tuesday.

Surgery revealed a wound about the size of a fist with damage to the pup's muscle and tendons. Veterinarians were able to avoid amputation but then had to figure out how to stop Nanook from "knuckling," or walking on top of his paw instead of on the pad.

They found a flexible boot made partly from Velcro that solved the problem, but warn potential adoptive families that Nanook may have to wear it permanently, and may also require regular massage therapy.

Wallach said it's unlikely any charges will be laid as it's difficult to gather evidence in the rural area.

"How it happened, we'll probably never know for sure. It's not unheard of for people in rural areas to shoot dogs that are trespassing on their property. It's not illegal for them to do that. That may be what happened with Nanook."