The parasite lives in the heart and pulmonary arteries of infected dogs, where it can cause damage to the heart, lungs, and other organs. Heartworms can also cause a number of health problems, including:
* Weight loss
* Coughing
* Difficulty breathing
* Fatigue
* Lethargy
* Depression
* Heart failure
* Death
Heartworm disease can be prevented by using monthly heartworm prevention medication and having your dog tested for heartworms annually. If your dog is diagnosed with heartworm disease, treatment is available but can be expensive and time-consuming.