Dog owners are being warned to stop their pets from scoffing slugs and snails in order to avoid a life-threatening worm living inside the slimy creatures.
Two dogs, in Feltham and Addlestone, have already died after becoming infected with potentially deadly lungworm and several more suspected cases are currently being treated.
Vet Leigh Sobye, who works for Willett House Veterinary Surgeons which has branches in Feltham, Staines and Addlestone, said: "We've already let all our customers know but we're very anxious that all dog owners be aware of the new dangers associated with slugs and snails.
"Lungworm have always been a problem down around Cornwall and South Wales but they seem to have spread up here - probably because of the increase in urban foxes. My suspicion is that this problem will spread all across the South East and eventually become endemic."
Dogs can become infected with the worm's larvae, which live in their hearts and lungs, after eating infected slugs and snails.
Symptoms can take years to develop but may eventually include coughing, depression, vomiting, diarrhoea, prolonged bleeding, fits, weight loss and exercise intolerance. Some animals will eventually die due to severe bleeds or end up with permanent brain or lung damage.