Update Jan. 28, 2018: Max took a turn for the worse on Jan. 27 died from internal injuries , his owners said.

A Vancouver man and his girlfriend say they've been left with an injured pet and a $2,000 vet bill after an attack by an off-leash dog whose owner fled the scene.

The incident occurred on Sunday in along the Coal Harbour seawall where it was captured on a nearby resident's surveillance video.

Farshid Tabari and his partner were taking 10-year-old Max for a walk around 12 p.m. when another off-leash dog came over. At first, they wanted to sniff each other, but the dogs soon started barking, and Tabari hoisted Max up by his harness to prevent a fight.

The other dog, however, went around Tabari, jumped up and yanked Max down.

"The harness is up there and Max is not there," Tabari said. "The dog is biting him."

Then, Tabari said, the dog's owner came over, pushed him away and accused him of kicking the dog.

"He didn't offer help or say, ‘How's your dog doing?’" Tabari said.

Things escalated when Max’s owner said he was going to call the police.

"He's walking away and I say, okay, I'm going to take your picture," Tabari said. "And he's coming back to me saying you take my picture? I'll break your camera, I'll sue you."

The man and a woman who was with him then left.

Tabari's girlfriend scooped up Max and they checked the dog for bleeding. When she put Max down, though, he immediately fell to the ground.

Days later, Max is still recovering. He's been left with bruising and can't walk properly yet. Tabari said an x-ray at the animal hospital revealed fluid in Max's body that could have been internal bleeding.

Friends of Max's owners have set up a GoFundMe page to accept donations to help cover his vet bills.

Tabari reported the incident to animal control and the Vancouver Police Department. The city told CTV it is aware of the incident and is investigating the attack.

"The owner of the offending dog has not yet been identified but if or when they are the City will take action," the city said in a statement to CTV.

It also encouraged anyone who has information about the incident to contact Animal Services via 311.

In Vancouver, dogs must always be kept on a leash unless they are at one of the city's 36 designated off-leash areas. There's a fine of $250 for a dog off-leash in public.

"If something happens, please be responsible and stay," Tabari urged. "Obviously you care about your dog. Why not care about other people's dogs?"

With a report from CTV Vancouver's Maria Weisgarber