Austin Forman was in his family's garden in Boston Bar with Angela, the family's 18-month-old pet dog, when he was charged by the wild cat.

Angel positioned herself between her young master and the cougar, sustaining puncture wounds.

"I was really scared. At first, I didn't know it was a cougar. I thought it was another dog," Austin told the Canadian news website CTV News on Sunday. "As soon as it went underneath the light, I saw that it was a cougar. I knew at that moment, I had to go inside."

The boy fled into his home, yelling: "A cougar is eating Angel!"

Sherri Forman, Austin's mother, called police, and a nearby constable from the RCMP sped to the scene, where the wild cat was attacking the dog.

The cougar had dragged Angel under the porch, where it continued to savage the dog's neck and face despite the officer firing two rounds into its hind quarters.

When the officer finally shot and killed the wild cat, its jaws remained closed on the dog's face.

When the cat was finally killed, the dog was silent for a few moments, then took a big gasp of air and got to her feet.

The dog, which has a swollen eye, was expected to recover with the help of a local vet.

Mrs Forman praised the family pet.

"She must've known something was up," she said. "Now, she's our guardian angel."