Mature heartworm infection, radiographs, cat

Ventrodorsal (A) and right lateral (B) radiographs from a 5-year-old male cat with a history of cough. Heartworm antibody and antigen test results were both positive, and worms were visualized within the main pulmonary artery on echocardiogram. Note the diffuse, bronchointerstitial pattern with a subtle nodular component. Caudal lobar pulmonary arteries are dilated and mildly tortuous (*). There is mild enlargement of the cardiac silhouette; however, wall thicknesses and chamber dimensions were normal on echocardiography. CVC, caudal vena cava.