Heartworm disease on radiographs: pulmonary arteries or veins
6-year-old hunting dog from Huelva (southern Spain), without prophylaxis, with cough and exercise intolerance. On the DV view the caudal lobar arteries are enlarged, tortuous and truncated, the main pulmonary artery bulges and the right heart is enlarged. The veins are normal.
What is the most accurate interpretation?
chevron_right Show answer and explanation
A. Venous congestion due to left-sided heart failure
In left-sided congestion the pulmonary veins are larger than the arteries and the left atrium is enlarged; here the veins are normal.
B. Arterial vascular pattern consistent with heartworm disease and pulmonary hypertension
Correct. Enlarged, tortuous, truncated arteries with a bulging main pulmonary artery and right heart enlargement are typical of advanced heartworm disease. Confirm with an antigen test and a microfilaria test (Knott).
C. Pulmonary overcirculation due to patent ductus arteriosus
In overcirculation both arteries and veins are enlarged, with left heart enlargement and, in PDA, bulges of the aorta and left atrium.
D. Hypovolaemia due to dehydration
Hypovolaemia causes small arteries and veins, a small heart and hyperlucent lungs, the opposite of what is described.
lightbulb Key takeaway
Compare the artery and vein of the same lobe: on the lateral view the cranial lobar artery lies dorsal to its vein; on the DV view the caudal lobar artery is lateral and the vein medial. Large arteries: heartworm disease or pulmonary hypertension. Large veins: left-sided congestion. Both large: overcirculation or volume overload.
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.