Heartworms are a type of parasitic roundworm that spreads throughout the dog's body infesting the heart of a dog. Heartworms cause heartworm disease which is a very serious potentially fatal disease for dogs, and cats.

Heartworms are parasitic invaders that are spread only by the bite of an infected mosquito. Heartworms can grow to over a foot in length, infesting the heart, lung, and other blood vessels of the animal's body.

If you think your dog may not have heartworms just remember over 250,000 dogs become infected with heartworms every year! Since heartworms pose such a serious threat to a dogs health it is very important to treat this disease as quickly as possible.

Heartworms can only be spread to dogs through a mosquito that is infected with heartworms. Heartworm disease is most commonly found in places where mosquitos have a naturally occurring high population, where they can flourish and spread the parasite more easily. However, heartworms are beginning to increasingly be found in areas where they were not as common before such as areas in the west coast, for example, California, Oregon, Washington. This is due mainly to urban development, and irrigation which has laid the foundation for mosquitos to spread and bring this disease with them. 

When the infected mosquito bites the dog it brings with it the heartworm larvae, these larvae then usually take 6 months to mature into a parasitic heartworm. Once they have reached full maturity these parasites can live up to 7 years inside the host's body wreaking havoc.