The son of a woman whose dog was killed in a tragic attack at the Esquimalt Lagoon is coming forward to share his side of the story – and says the incident was entirely preventable.

Riley Clarke says he and his mother took her small terrier to the off-leash area of the lagoon Monday afternoon when the dog started to chase birds.

The terrier got closer to an American bulldog also at the lagoon, so the bulldog's owner leashed the animal and took it further down the beach for a game of fetch, according to CRD Animal Control.

Clarke said the terrier chased a bird down to the same part of the beach, and when it ran past the bulldog, the larger dog turned and grabbed it in its jaws.

"By the time I heard my mom yell and scream, I turned around and the dog was shaking the terrier. He was trying to kill it, there's no two ways about it," said Clarke.

He said as his mother was crying and screaming, the owner of the bulldog tried to pull his dog off the terrier unsuccessfully.

"He ended up falling down himself and he wasn't actually able to get back up on his own, so that's when my mom was screaming 'Call 911, call someone.' She was frantic and distraught," said Clarke.

The terrier was pronounced dead. While the owner of the bulldog was under no pressure to put his dog down, he told CRD Animal Control that's what his intentions were.

"He followed up with us to confirm that that had been done," said Saanich Chief Bylaw Officer Don Brown.

A CRD bylaw states that owners of dogs must ensure their dogs do not harass people or animals, even in off-leash areas.

Brown said in the worst cases, owners can be charged under the BC Offence Act, which carries penalties up to $10,000.

Clarke said the bulldog owner should have taken extra precautions if he knew his dog was aggressive. He also said he didn't want the bulldog to be euthanized, and if anything, it should have been rehomed.

"I feel like two dogs lost their lives because of a neglectful owner," he said. "I have a bulldog. It's not the breed at all, it's the fact that two dogs lost their lives because of a mistake that was so easily preventable, even just communicating that it could be aggressive."

Brown said the bulldog owner was cooperative with him immediately after the incident.

He's reminding owners to be constantly be aware of their dog's behaviour and mood to avoid tragic attacks like this one.

"You have to be cautious and watch your dog at all times, and obviously if there's something happening, if the dog is acting aggressively, get it out of there immediately," he said.

No charges have been laid.