A Whistler veterinarian is worried heartworm disease may have spread to other dogs in the community but, the only way to find out if the disease has established itself locally, is to have all dogs tested before the start of the mosquito season. Dr. David Lane of Coast Mountain Veterinary Services says a dog that had been living in Whistler for the past three years was diagnosed with the disease last fall. Although it is presumed the pet may have been infected elsewhere, there is some concern the disease may have had to opportunity to spread. According to Lane, heartworm disease is a parasitic condition in which microscopic worms penetrate the skin and then migrate through the dog’s body until they reach the blood vessels of the lungs. By this time, they have grown into adults they can impair the flow of blood. Depending on the severity of the infections, the worms may start to fill certain chambers of the heart, leading to heart failure. The clinical symptoms range from no signs at all, to a persistent dry cough, difficulty breathing and a lack of energy, to kidney failure, heart failure, sudden respiratory disease and death. Cats, on the other hand, are fairly resistant to heartworm infection and are only considered to be at risk in areas where the disease is known to be established. Heartworm is spread by mosquitoes and can only survive in certain areas. The warmer the climate, the greater potential for the parasite to thrive. Lane sys the only way to be sure the disease has not established itself locally is to have all dogs tested. There is no need to test cats at this time, he said. The ideal time for a test is between April 1 and the start of the mosquito season. Protective medications are available to prevent future heartworm infections but are only advised if it is determined the disease has established itself locally. Dogs travelling to the Okanagan, United States or east of Alberta should be protected by a heartworm preventative medication.