Heartworm

Heartworm is a preventable, serious parasite that primarily infects dogs, cats, ferrets and a variety of wild animals. There have been rare cases documented in humans but these do not usually result in any signs of illness.

Heartworm is transmitted from animal to animal by mosquitoes. When a mosquito bites an infected animal, young heartworms (called microfilariae) enter the mosquito's system. Within two weeks, the microfilariae develop into larvae inside the mosquito. These larvae are then transmitted to another animal when the mosquito bites it. During the first few months, the larvae move through the animal's body and eventually reach the blood vessels of the lungs. The larvae continue to grow and develop into adult heartworms, up to 14 inches long. The worms damage the vessels and reduce the heart's ability to pump resulting in severe heart and lung disease.

Although heartworm can be treated in dogs, it is much better to prevent heartworm infection. There are several heartworm preventives on the market - your veterinarian can recommend the best method based upon your pet's risk factors and lifestyle. It is important to test your dog for heartworms BEFORE starting preventives each year.