Infection with Cruorifilaria tuberocauda caused vascular damage in the kidneys, lungs and heart of the capybara (Hydrochoerus hydrochaeris). The most significant lesions observed were in the renal and pulmonary arteries. They consisted of villous endarteritis, intimal and medial hypertrophy of the vessel walls, and large rugose protuberances that encroached upon the lumen leading to pyramidal infarcts in the kidneys. Coronary vascular lesions were related to dead and calcified parasites.