Subaortic stenosis in a 2.9kg, 3-month-old pug dog and a 11 kg, 4-month-old Rott -weiler dog showing signs of dyspnea, tachypnea, anorexia, exercise intolerance and depression was diagnosed with electrocardiography, thoracic radiography and ultrasonographic evaluation. In electrocardiography, PR interval widening, R wave amplitude increase in lead II in case 2, ST segment depression and left axis deviation in case 1 and 2 were identified. In thoracic radiographs, enlarged left ventricle and atrium, caudal displacement of left crus of diaphragm and caudal part of cranial mediastinum widening were identified in ventrodorsal view. In lateral view, left ventricular enlargement, secondary dorsal deviation of trachea and post-stenotic dilation of aorta were seen. Also, edematous pulmonary changes were shown in peri-hilar area. In ultrasonographic examination, left ventricular dilatation, pericardial effusion and subaortic valvular ridge were seen with real time B-mode in right parasternal long axis view. Aortic valve regurgitation was identified in color-Doppler mode.