The warm weather is upon us and with it, the return of insects and parasites that can affect your pet. We all know mosquitoes and the unpleasant itching after their bites. But did you know they can also carry parasites potentially fatal for your pet ?
Indeed, heartworm disease, commonly known as the '' heartworm '' can affect various mammals, especially dogs. The parasite Dirofilaria Immitis lives, when mature, in the heart and pulmonary arteries. The cycle begins when a mosquito feeds in an infested animal and ingests heartworm offspring ( microfilariae ) into the bloodstream of it. In two to three weeks following, non-infectious microfilariaes develop into infective larvae within the mosquito. Returning to feed on a dog, the infected mosquito transmits the parasite to a new host. Once in the tissues of the dog, the infective larvae continue to develop and migrate to the heart where they reach the adult stage. Approximately 6-7 months after infection, if a parasite of both sexes are found in the heart, they will begin to produce microfilariae. The life expectancy of the adult heart worms can grow up to 7 years.
An infected dog becomes a source of infection for himself and for the neighborhood. Transmission is necessarily via the mosquito and never by direct contact between dogs. It is important to do the prevention during the summer, and as long as mosquitoes are present. A heartworm infested animal may show no sign for several months, and sometimes years. Others demonstrate symptoms such as : mild to chronic coughing, exercise intolerance, labored breathing and in extreme cases, heart failure that can lead to a collapse or death.
To avoid infection, treatment is given once a month, orally or applied to the skin of the dog. Prevention must last from June to November, as long as warm weather is here and there are mosquitoes.
Before starting preventive treatment, testing will be performed on all dogs. At the Ste-Rose Veterinary Hospital, we use the 4DX test. With a simple blood test, we test for heartworms, but also for other diseases transmitted by ticks as Lyme disease. This test is recommended annually, but when dogs get their prevention diligently each year, we perform this test every 2 years.
This allow us to ensure that the animal receive properly and respond well to medication. Early screening allow us to respond correctly and adjust our approach if the animal get infected, and become an source of infection for his neighborhood.
Remember that, as it's the mosquito that transmits heartworm, if you go south with your pet during the winter, it will be important to continue to address this during your stay there.
The image attach to this article is a plastic model representing a adult heartworm in a heart.
Marie-Christine Hamelin, Veterinary Technician