Dogs with late stage filarial infection

Canine heartworms are mainly found in the heart and pulmonary arteries and the clinical signs include coughing and difficulty breathing. In fact, canine heartworm disease is often found accidentally. An enlarged right ventricle or thickened pulmonary artery on X-ray can be used to suspect heartworm disease, and the final diagnosis can be made by cardiac ultrasound or blood smear.