Public health issues concerning the widespread distribution of canine heartworm disease.

Heartworms can cause serious cardiopulmonary disease in their canid hosts. Canine heartworm has become widespread in many parts of the world, and its range continues to expand. Wildlife reservoirs play a role in perpetuation and transmission of this parasite to dogs. Human heartworm infection is incidental and is typically not associated with severe clinical disease; however, because no serological test is readily available, patients must undergo invasive procedures to differentiate heartworm from other more serious diseases. Human cases have been reported mainly in areas of high canine prevalence, highlighting the importance of heartworm testing and chemoprophylaxis in all dogs to reduce transmission. Future efforts should focus on the development of a non-invasive diagnostic test for people, and on epidemiological surveys for both animals and people.