Heartworm Introduction

Introduction
Heartworm disease has been found in all 50 states in the U.S. Its prevalence has increased because we live in such a mobile society - people and their pets travel from place to place, unknowingly taking parasites along for the ride. Dogs of any age and breed are susceptible, and the disease can be fatal.



The parasitic worm responsible for heartworm disease is called Dirofilaria immitis. The life cycle of the heartworm begins when a mosquito bites and feeds on the blood of an infected dog that is carrying tiny immature heartworms, called microfilariae, in its blood. The mosquito takes in the immature heartworms when it feeds. During the next two-to-three weeks, the larvae develop into the infective stage within the mosquito. When the mosquito feeds again, it can transmit infective larvae to a healthy dog. The larvae enter the dog's body through the mosquitos bite wound , migrate through its tissues, and develop over the next few months, eventually reaching the dog’s heart and lungs. Heartworms may be present in the heart and lungs approximately four months after initial infection. Once in the dog’s heart, the worms may grow to between 7 and 11 inches in length. and cause significant damage to the heart and lungs. If left untreated, heartworm disease may result in death. After adult heartworms mate and produce immature heartworms an infected dog which is bitten by an uninfected mosquito will transmit microfilariae to the mosquito, beginning the cycle again. The life cycle of the heartworm is approximately 6 months.

Whether your dog spends lots of time in the great outdoors, rarely ventures out of your own back yard, or is strictly an indoor dog, it’s at risk of exposure to heartworms, as well as gastrointestinal parasites. In fact, unless your dog is protected, these common parasites can endanger its health. Fortunately, heartworm disease can be prevented, and gastrointestinal parasites can be treated and controlled.