Residents on Cheung Chau say packs of feral dogs roaming the island are killing domestic pets and pose a threat to young children. 'It's not a new problem but it has been getting worse,' resident Antonia Cable said. 'In recent months, the dogs have moved closer [to residential areas].' Cable said packs of up to 12 dogs had been 'terrorising' the island. Her neighbour on Pak She San Tsuen had three cats killed in an attack by a pack of dogs last week. The cats were in a garden surrounded by a fence when attacked. Unlike stray dogs, which might be abandoned or get lost, feral dogs are born in the wild. Cable said she had sighted at least 40 feral dogs on three Cheung Chau streets - Pak She San Tsuen, Siu Kwai Wan and Peak Road. She said the dogs also posed a health risk because they scavenged for food in piles of rubbish and dragged it around at night. Rubbish was strewn everywhere by morning. She was especially concerned about the safety of her two children, who are three and five years old, after she had seen packs of dogs outside her front door. She also worries that seven cats she cares for under the SPCA's Cats Colony Program might be attacked. Dr Martin Williams, an environmentalist and Cheung Chau resident, said dogs had killed a cat that he 'inherited' from the previous tenant of his flat a few months ago. Williams said his landlord had found the cat's body and disposed of it. 'It's an ongoing problem,' he said. Williams said the authorities had mounted a big operation years ago and taken away a large number of dogs, but the remaining few eventually started breeding again. Although he was sympathetic to the plight of abandoned dogs, he hoped there would be some effective control over the problem. A spokesman for the Agriculture, Fisheries and Conservation Department confirmed it had received a complaint in mid-January and subsequently carried out four daytime operations. Four dogs were captured and removed. But Cable said the operations proved ineffective because the extent of the dog problem was not apparent during the day, as the dogs were only active at night. SPCA spokeswoman Rebecca Ngan Yee-ling said the safety of the public and their pets had to be balanced against the lives of stray animals. 'We all know what happens to the animals that are caught [by the AFCD],' she said. The SPCA has been advocating the desexing of stray dogs for many years. The animals were usually less aggressive once desexed and their number gradually reduced naturally. Ngan said the Cats Colony Program, which involves treating and desexing stray cats had worked well for the past 10 years. But a similar policy for dogs had not gained broad acceptance in the community, with members of the public expressing concern about stray dogs attacking people or pets. She suggested people take extra effort to make sure rubbish was disposed of properly. This would make it more difficult for dogs to scavenge for food and would discourage them from roaming residential areas. Ngan said keeping domestic pets indoors was safer than leaving them outside. But if that was not possible, it was important to ensure gardens were properly fenced. The AFCD spokesman said whether a night operation was mounted on Cheung Chau would depend on the situation and resources available.