Partial Pulmonary Vein Stenosis in a Cat Treated with Sildenafil: A Case Report

Abstract

: We report the case of a 2-year-old Norwegian Forest cat diagnosed with pulmonary edema and pulmonary hypertension (PH) secondary to cor triatriatum sinister, who showed improved breathing following furosemide treatment. Sildenafil was prescribed post-discharge without diuretic. Thirty-eight days later, no abnormalities were observed in the septum or accessory chamber of the left atrium; however, continuous mosaic blood flow (maximum velocity, 3.14 m/s) was observed in two enlarged pulmonary veins. Pulmonary artery enlargement (main pulmonary artery to thoracic aorta ratio: 1.90), pulmonary vein stenosis (PVS), and diffuse bilateral ground-glass lung opacities were observed using computed tomography. PH with partial PVS and pulmonary parenchymal disease was diagnosed. The cat was further treated with furosemide with no clinical symptoms, but succumbed to acute dyspnea 51 days after the first visit. PH, despite partial PVS, may also be associated with concurrent parenchymal lung disease. Sildenafil can worsen pulmonary edema in the affected lung but did not in this case.