A Worm Deadly to All Dogs

Heartworms (Dirofilaria immitis) are the most dangerous and deadly parasitic worms to infect dogs, and are why mosquitoes, the vector that spreads these parasites, are so dangerous. Unlike most parasites, heartworms are deadly to the healthiest of adult dogs.

To understand the danger of the heartworm and importance of preventing heartworm infections, one must understand its life cycle.