This web page was produced as an assignment for an undergraduate course at Davidson College.

Life Cycle

Adult heartworms (D. immitis) live in the pulmonary artery and right chambers of the heart. The lifespan of the worm is about 5 years. During this time, thousands of immature heartworms, known as microfilariae, are produced. Microfilariae live in the blood stream and small vessels of the circulatory system. They cannot achieve maturity within the host, though, and must spend some of their lifecycle in a mosquito.

Female mosquitos act as a vector for this pathogen and ingest immature microfilariae during bloodmeals. An overview of the lifecycle of the worm follows.

Complete maturation occurs within the host:

The lifecycle of D. immitis (Courtesy John Vilhauer

Department of Nematology at University of California, Davis. 2005 March. <> Accessed 2007 April 20.

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