A Victoria man is demanding justice for his dog Cooper after it died the day after an altercation with an animal he describes as a mixed breed white pit bull.

Since the incident on Saturday, Paul Johnston says he has heard from at least four people who have had similar encounters with the same animal and its owner.

Maltipoo Cooper was fond of going on mountain hikes with owner Paul Johnston. (Paul Johnston)

The 29-year-old says Cooper, who would have turned three in June, is his closest companion. The pair often hike up Mt. Finlayson in popular Goldstream Provincial Park, close to Victoria.

However, this week, when Johnston and Cooper reached the summit, he says they encountered a mixed breed white pit bull and its owner.

According to Johnston, the animal was being held by the collar as Cooper shied away from it. Neither dog was on a leash even though the park requires it.

Johnston said somehow the pit bull got loose and clamped its jaws around Cooper's neck and belly.

"The owner was frantic saying this has happened before and he was worried about me putting down his dog," said Johnston. "So I grabbed his dog as hard as I could behind the ears to try to release the jaw."

A photo Paul Johnston took of his dog Cooper at hospital after an altercation with another dog. (Paul Johnston)

Johnston says the owner never once called his animal by name during the encounter and that he did little to call it off.

"I repeatedly hit his dog in the stomach to try to get the release," said Johnston. "I saw that his canines, the left side of the canines were digging into my dog so I put my hand between my dog and his dog to stop him from biting completely through my dog."

Finally the pit bull released Cooper.

Two hikers helped Johnston bandage him up and stop his bleeding.

Dog's owner leaves

"And that took approximately a minute or two," said Johnston. "Now I poke my head up. I say 'hey where's the guy?' and the one hiker said he took off."

With the help of the hikers Johnston carried Cooper about 1.5 kilometres down the mountain, and rushed him to an animal clinic.

Johnston says he needed stitches to repair the damage to his fingers sustained in his struggle with the dog.

Unfortunately, on Sunday, the animal hospital called around 5 a.m. PT to tell Johnston that Cooper had died in surgery from a blood clot.

Cooper died from a blood clot after veterinarians performed surgery to close the dog's wounds. (Paul Johnston)

"It's like a punch in the gut that's for sure," he said "It's like losing your best friend. There's honestly no words that can describe how it feels."

Johnston has asked Capital Regional District animal control officers to investigate the attack, especially since he's received calls from others who claim their animals have been involved in incidents with the same dog.

"I would like for the guy to be caught," he said. "This could devastate another family. A dog is like a part of your family. Or it could be a child. And like I said I'm a pretty decent-sized guy and it took all my might and my strength to get that dog released off my dog."