Heartworm, West Nile Virus and Your Dog

Dog owners need to be aware of Heartworm and West Nile Virus if they live in or are traveling to areas heavily infested with mosquitoes.

Heartworms are parasites that live in the blood of an infected dogs’ heart and surrounding blood vessels. They are transmitted to the dog (host) by the bite of an infected mosquito. The adult worms live in the heart of the host and produce offspring (microscopic larvae) called microfilariae. These small larvae circulate in the dogs’ blood. When a mosquito bites the dog, it ingests blood containing microfilariae which are then passed on to the next dog that the mosquito bites.

These nasty little creatures can cause serious problems for dogs by enlarging the heart, restricting blood flow and damaging internal organs. It can usually be treated with drugs, but the best way to treat heartworm is with prevention. Talk to your veterinarian about treatments prior to traveling to a mosquito infested area.

The high risk areas for heartworm in Canada are southern Quebec, southern Ontario, Manitoba and the Okanagan area in British Columbia. There are very few reported cases in Alberta and Saskatchewan, but prevention is still the best cure, even in those provinces.

West Nile Virus is also spread from host to host by infected mosquitoes. The mosquito bites an infected host, usually a bird, but can be horses or other species. The virus incubates for 5 - 15 days in the mosquito, which then transmits it to the next host it bites, which could be a dog. Dogs apparently can get the disease but do not show clinical signs of having it.

Using a mosquito repellant specifically designed for dogs, not being outside at active mosquito times like dawn and dusk and taking any veterinarian prescribed preventions will help protect you dog from mosquito transmitted diseases.