Abstract
Patent ductus arteriosus (PDA) is relatively common congenital heart anomaly in dogs but is rarely reported in cats. This report describes the diagnostic evaluation of a 6 years old neutered male domestic shorthair cat presented with exercise intolerance and mouth breathing during stress. Physical examination revealed a continuous machinery like murmur at the left heart base and bounding femoral pulsation. Thoracic radiography demonstrated cardiomegaly, a broncho-interstitial lung pattern, and pulmonary venous enlargement. Echocardiography confirmed a left to right shunting PDA with evidence of left atrial and left ventricular dilation (LA/Ao ratio is 1.68, left ventrivcular internal diameter during the diastole (LVIDd) is 31.8mm). Hematology illustrates mild anemia and biochemistry demonstrated elevated ALT activity, with other parameters within normal limits. Surgical correction was discussed with the owner but declined. This case highlights the diagnostic approach and clinical relevance of PDA in cats and emphasizes the importance of auscultation and echocardiography in the recognition of congenital cardiac anomalies in feline practice in Egypt.

Key words: Patent ductus arteriosus, cat, echocardiography, congenital heart disease, cardiomegaly