Severe radiographic lesions of canine heartworm disease in a 6-year-old Boxer, lateral projection. Note increased sternal contact and dorsal displacement of the apex of the heart caused by right heart enlargement (unlabeled arrow), severely enlarged and tortuous pulmonary arteries, and moderately increased bronchointerstitial pulmonary infiltrate. Small metallic pellets in the soft tissues are incidental findings. MPA & RA, main pulmonary artery and right atrium; RV, right ventricle; PA, pulmonary arteries; PIE/PTE, pulmonary infiltrate with eosinophils/pulmonary thromboembolic embolism; CVC, caudal vena cava.