The heartworm is a parasite transmitted by the mosquito.
When a mosquito bite an animal infected by the heartworm, it ingests the offspring (microfilariae) discharged by the females in the bloodstream. In 2 to 3 weeks following non-infective microfilariae develop into infective larvae in the mosquito. Returning to feed a dog, the infected mosquito transmits the parasite. Once in the tissues of the dog (skin), infective larvae continue to develop, migrate to the heart where they reach the adult stage and begin to produce microfilariae if both sexes of the parasite can be found in the heart. An infected dog becomes a source of infection for himself and for the neighborhood. Transmission is via the mosquito and not by direct contact between dogs. It is important to do prevention during the summer. A animal infested with heartworm may show signs of mild to chronic cough, exercise intolerance, of labored breathing and, in extreme cases, of collapse as a result of heart failure in the effort. The treatment is given once a month by one oral or topical during the summer months from May to November. A blood test is done every 2 years to ensure that the animal meets the preventive treatment. If you go on a trip in the winter with your dog for hot countries, it is also important to treat the animal during this period.