Canine Heartworm Disease

Mosquitoes, infected with the parasite named Dirofilaria immitis, transmit heartworm infection to your dog when the mosquito takes a blood meal. In the early stages of disease, when the heartworms are immature, your dog may not show any signs of a problem. Once mature, the adult heartworms lodge within the blood vessels of the lungs, creating inflammation, seen as a cough and exercise intolerance. As the worm burden multiplies, the worms fill the right side of the heart impairing its function. The most advanced stages of heartworm infection cause signs of right sided heart failure including lethargy, collapse, swelling of the limbs, abdominal distension, and weight loss. Heartworm infection is diagnosed with a simple blood test that detects the presence of adult female worms. Dogs found to be positive for heartworm infection need further diagnostic testing (e.g.: blood work, chest x-rays) to determine the extent of the disease, develop the safest treatment protocol, and monitor therapy. Therapy for heartworm infection requires a series of injections to kills the heartworms. Treatment with this medication requires absolute cage rest following the injections to avoid complications from pulmonary thromboemboli as the worms die. The safest, most effective treatment for heartworm disease is prevention: treat the infection before the worms mature and lead to disease. Monthly, year-round prophylactic medications prevent this life threatening disease.