An animal welfare organisation believes a dog fighting ring is behind a rise in the number of dogs going missing, but the SPCA doubts that's the case.

Chad Laboyrie hopes his seven-month-old American Bulldog, Billy, hasn't suffered such a fate, after she was taken from his home in Ohaupo, near Te Awamutu, four weeks ago.

Mr Laboyrie said he believed Billy was stolen to be used for breeding, as she wasn't fixed, but said he was extremely worried about how she was being treated.

Mr Laboyrie said he had set up the Facebook page Bring Billy Back, which had received more than 3000 likes.


He and his partner, Margot, shared photos of Billy in the hope that if more people knew about her, she was more likely to be returned.

"She was part of the family. I would have rather had my whole house cleaned out. That stuff is replaceable," he said.

"We won't stop looking for her. She has to pop up somewhere."

Mr Laboyrie said since he created the Facebook page more people had told him about their dogs being stolen.

"I've been talking to people and it's quite crazy the amount of dogs that actually get stolen.

"No dog is really safe."

There was in increase in the number of dogs being reported missing, said Craig Dunn, a spokesman for Paw Justice -- an organisation that works to reduce animal abuse.

He said he was getting at least one phone call a day from all parts of the country in relation to missing dogs.

It was more than likely the dogs were stolen to be used as bait or to be trained as fight dogs, he said.

Mr Dunn said the best best way to prevent these crimes was through awareness.

People loitered around dog parks, followed dog owners home, marked the footpath outside their homes and someone would come back later to take the dog, Mr Dunn said.

"I encourage people to get together and watch out for this sort of thing."

However the SPCA had seen nothing to made it think a dog fighting ring existed, Auckland SPCA chief executive Christine Kalin said.

"There is no evidence dogs are being taken for these reasons.

"The difficulty is there hasn't been any real analysis about how many dogs in what areas have gone missing, so it's difficult to say what's going on."

Ms Kalin said they obviously did not want to see dogs separated from their families, and encouraged owner responsibility to ensure dogs did not go missing.