After three family pets were maimed, murdered and dumped in front of their owners' South Auckland homes, the community is concerned a serial animal killer is on the loose.

When Donna Williams went to feed her rabbit, Lucky, on the morning of May 8 he wasn't in his cage.

She found Lucky dead on the front lawn of her Papakura home. He had been decapitated and his front paws were cut off.

"It was pretty devastating. I was very upset. He was really good mates with my little dog," Williams said.

She then found her neighbour's rabbit not far up the road. It had also been attacked and killed, its face cut off.

The attacks were reported to the police and SPCA.

After an autopsy and a police examination of the cages, it was deemed the attacker was definitely human and not dogs.

However, Williams and her neighbour were advised that the police could do nothing.

On Monday, the Newby family, of Karaka, found their mutilated fox terrier dumped on their front lawn. It had been skinned and a paw and its ears were missing. Six-year-old Portia had been missing since Wednesday last week.

"She was a delightful little dog; she wouldn't hurt anyone," Kelly Newby said.

"What's worse is someone snuck on to our property and dumped her on our back lawn under the clothesline, where my kids had been playing."

Williams believes the attacks were done by the same person. She has also heard of a goat being attacked and maimed in a similar way.

"There is some psycho out there. What is he going to do next?" she said.

The attacks have left Williams and her family concerned for their animals and those of the community.

"I would never leave my little dog unattended. We have cats too and I am worried about them because they go out at night," she said.

The attack on Lucky happened just two weeks after Williams, her daughter, her sister and two nieces had moved into the neighbourhood. They have bought a staffordshire bull terrier cross for protection.