The dog poisoner who has killed dozens of pets in Mid-Levels may also have been operating in the New Territories, the Society for the Prevention of Cruelty to Animals (SPCA) says. Executive director Chris Hanselman said SPCA inspectors were gathering information about poisoning cases in the New Territories that bore the hallmark of the killer who has terrorised dog owners on Hong Kong Island. 'The poisoner is a lot more prolific than we thought and we are making some inquiries in the New Territories. We had thought the dog poisoner was targeting just expatriate dog owners but this is not the case,' he said. Dr Anita Tomasov, of the Victoria Veterinary Centre in Sheung Shui, said yesterday she had treated three dogs that were poisoned in the first week of December in Sheung Shui and Fanling. Two died and one survived, she said, adding the dogs were showing the same clinical signs as the poisoned dogs in Mid-Levels, such as nerve twitching. In the last series of attacks from December 1 to 3 in Mid-Levels, four dogs died and at least five were taken ill after eating insecticide-laced chicken. Another case has now come to light, with dog owner Georgina Middleton telling the South China Morning Post that her labrador was poisoned on December 9 around the Shiu Fai Terrace access to Bowen Path. Her nine-year-old son, who was walking the labrador, knocked the dog's face away from the tainted meat and in the process covered his hands with poisonous crystals, Mrs Middleton said. 'I hate to think what would have happened to my son had he not been responsible enough, rushed home and told me what happened,' she said. Her son did not ingest any of the crystals and the pet survived. Lee Chau-wing, senior chemist at the Government Laboratory, said yesterday the pesticide carbofuran had been used in most of the dog-poisoning cases dating back to the 1990s, including last month's incidents. 'It is a quite poisonous substance. It is odourless and kills by inhibiting the enzyme that is important in the transmission of the nervous system,' he said. Mr Lee said the poison would have the same effect on humans and could kill if someone ate a lot of it. 'It requires tens of granules to kill humans. If only a few were ingested accidentally, it could still have ill effects,' he said. It was not known if the New Territories cases involved carbofuran. The SPCA has launched a 'stop-the-poisoner' campaign for Mid-Levels dog owners to fight back. So far about 20 had signed up, public relations manager Simon Leung Pak-suen said. The SPCA hope more dog owners can help by calling its 24-hour hot line on 2711 1000 or e-mail firstname.lastname@example.org .