What Is Heartworm Disease?
Canine heartworm disease develops when a dog is bitten by a mosquito carrying microscopic heartworm larvae (juvenile worms) of a parasite called Dirofilaria immitis.
As a mosquito feeds, these microscopic larvae are deposited on the dog and quickly penetrate the skin to begin their migration into the dog’s bloodstream.
Adult heartworms can grow 10-12 inches in length and make their home in the right side of the heart and pulmonary (lung) arteries, often causing lung disease and heart failure.
Adult heartworms can grow 10-12 inches in length.