"Following an investigation, it was deemed the incident was not serious enough to trigger seizure of the dog," the council said in a statement. Officers issued four fines to the dog owner in January and February, relating to an animal biting a person, allowing a dog to be "at large" at night, and failing to register two dogs. The male dog believed to be responsible for the attack on the 10-year-old is a South African boerboel, the council said. Male breeds of the dog can weigh up to 90 kilograms once they are fully grown.

The second dog, which had also been seized, is a bull mastiff. Neither of the dogs was registered with the City of Casey, the council said. On Monday, the council requested that the owner authorise that the dog responsible for the attack was destroyed. The council confirmed just before 4.30pm that the dog had been euthanised with the owner's consent. Loading Replay Replay video Play video Play video

Neighbours rushed to the home after hearing screaming and seeing the girl's sister, 7, calling for help about 8pm on Sunday night. The girls' mother had left them home alone while she went to the gym, neighbours said. Jimmy Baird, one of a group who rushed to the girls' aid, said he was confronted by a "massive" dog, "going berserk". He said he feared for his own safety as he and other neighbours tried to distract the frenzied dog to rescue the girl. The house in Berwick where the attack occurred. Credit:Justin McManus

"I opened the door and just saw this big frothing head coming through the door," he told radio station 3AW. "I managed to get door closed again but the girl was still out there. "We couldn't get her out because [the dog] was just going berserk. It was just massive. It was shaking the whole window frame". The animal was one of two dogs in the backyard. Only one is reported to have attacked. Jimmy Baird, one of several neighbours who rescued the girl. Credit:Justin McManus

Neighbours worked together to distract the dog while the girl was retrieved from the backyard. But Mr Baird said she'd been badly mauled. "The poor girl was in a bad way," he said, with bite marks "from her ears down". The girl's sister described her sibling being thrown around the backyard "like a rag doll," Mr Baird said. He said she was covered with blood and dirt and her injuries were so extensive, the neighbours had difficulty carrying her.

"We didn’t realise how bad it was until they started cutting her clothes off,” he said. A neighbour drove the younger sister to several gyms in the area in an unsuccessful attempt to locate the girls' mother following the attack. Kerrie Baird said the mother and a male friend arrived home about an hour later. Mr Baird said he was glad he and the other neighbours had been home because the dog "obviously wasn't going to stop, you know". He told 3AW he had heard the family's two dogs at the property but had never seen them.

"I don't want to see them again either," he said. Another neighbour, who didn’t want to be named, said he often heard the dog - which he described as very large - barking, but said it lived inside and he had never seen it taken for walks. The attack comes just days after the death of a one-year-old girl, killed by her family's dog in northern New South Wales. The baby died on the way to hospital after being attacked by the family's Rottweiler. Senior lecturer in Animal Behaviour and Veterinary science at the University of Adelaide, Doctor Susan Hazel, said there was no single reason why dogs attack people.