Dog Heartworm Disease

Cause & Regional Issues

Heartworm disease in dogs and related canines is caused by a filarial nematode (a large thread -like roundworm), Dirofilaria immitis. The adult worms live in the right side of the heart (right ventricle) and adjacent blood vessels (pulmonary arteries), and because of their location, are commonly called “dog heartworms.” Heartworm disease occurs worldwide in most tropical and subtropical regions, with increasing frequency in temperate climates. For most of North America, the danger of infection is greatest during the summer when temperatures are favorable for mosquito breeding. In the southern U.S, especially the Gulf Coast and Florida, where mosquitoes are present year-round, the threat of heartworm disease is constant.

Cycle of heartworm disease in dogsSymptoms

Visible signs of heartworm disease may not appear until a full year after a dog is bitten by infected mosquitoes. In fact, the disease may be well advanced before the dog shows any symptoms. Typically, dogs with heartworm disease fatigue easily, cough, and appear rough and not thriving.

Potentially Fatal - Consult Your Veterinarian

Heartworm disease in dogs and cats is a serious and potentially fatal disease. Always consult your veterinarian for treatment and prevention of the heartworm disease in dogs and cats.

For more information please visit the Florida Cooperative Extension's Electronic Data Information website.