TWO dogs leapt a backyard fence in Hilton and massacred 31 guinea pigs early Saturday morning.

Leeanne Thwaite breeds the huggable rodents for show — they’ve won many awards — but they’re also her beloved little pets.

“I was just horrified,” she says, having awakened to see the dogs still in her Snook Street yard.

“They were rolling around on the grass enjoying themselves.”

The dogs — muscular pitbull-style bitzers — hopped back over the fence when Ms Thwaite went outside. She found her pets’ corpses scattered across her yard, and says “the sad thing is they’re lying in their little breeding pairs”.

“I have five left, that’s the smallest number I’ve had in 10 years.”

She’d worked for more than six years to breed her own specialised line of “self lilacs,” mixing various colours and coat types to get just the right mix. None survived.

“My whole hobby’s just gone down the toilet in one night of madness.”

The cages had been forced open by the dogs. One survivor was just a few days old. Now named Miracle, the infant was the only one of its litter of four to evade the dogs.

While guinea pigs can die of shock, the dead were soggy with dog saliva: one survivor had clearly been gnawed on. A heavily pregnant sow managed to escape the first round of the massacre but the dogs later found her too.

Ms Thwaite says as prey animals they would likely have frozen when confronted by the dogs.

”If they’re on the lawn they would just sit terribly still, they just sit still and hope they won’t be noticed.”

Ms Thwaite’s security cameras caught the dogs, running down the side of the house, and she’s hoping someone can identify them for the safety of other animals — or children — in the area.

The attack came two months after rabbits were killed on nearby Hewson Street in similar circumstances and a month after a cat was killed on Butson Street.

Ms Thwaite called Fremantle city council rangers who believe the dogs live over the border in Hamilton Hill (in Cockburn council area).

The Herald contacted both councils and they’re currently sharing information to find out who owns the dogs. Cockburn community safety manager Rob Avard says anyone who sees dogs roaming off leash should call their council. Cockburn rangers are 9411 3444 and Freo 1300 360 666.

One of the dogs is brown with a white front foot and a white tip on its tail, likely a boy. The other is a female who’s recently given birth judging by her teats, which a white tip on her tail and a white patch on her left ear and head. She’s a bit skinny and is missing some hair on her rump.

by DAVID BELL