Question of the Day

Adult heartworms (HW) live primarily in the pulmonary arteries. With high worm burdens, they may also extend into the right ventricle. HW cause damage to the arterial lining cells which results in inflammation. This inflammation causes narrowing of the pulmonary arteries which increases vascular resistance and results in pulmonary hypertension.

Exercise worsens the pulmonary artery pathology and active dogs are more likely to develop overt clinical signs of heartworm disease such as right-sided congestive heart failure.  

Perform thoracic radiographs in dogs with clinical signs of HW disease. Look for enlarged, tortuous pulmonary arteries and right ventricular enlargement, which together indicate pulmonary hypertension.