July Pet Vaccine Special

What Is Heartworm Disease?

Heartworm disease is a serious, potentially fatal disease in dogs, cats, and other mammals. It is caused by parasitic worms which live in the heart and other adjacent large blood vessels of infected animals. Heartworm disease had been reported in all 50 states and is most problematic an areas where mosquitoes are prevalent.

Heartworm Life Cycle

Heartworm Disease in DogsDogs or other animals infected with Dirofilaria immitis are the reservoir for heartworm disease. The life cycle begins when a female mosquito bites an infected animal. Mosquitoes become infected with microfilariae, the larval form of the worm, when they take a blood meal.

Once in the mosquito, the microfilariae mature into the infective larval stage. Then when the mosquito bites another susceptible animal, the larvae is introduced into the new host.

A mosquito, the intermediate host for the worm, is required for transmission. It isn't spread directly from dog to dog. It takes about 2 months for these larvae to migrate into the animal's venous blood stream and to arrive to the vessels of the lungs.

It takes a total of 6 months for larvae to mature into adult heartworms which produce more microfilariae. Adult worms may live up to 5-7 years in the dog.