Abstract
A rare case of an unruptured sinus of Valsalva aneurysm (SVA) in a 2-month-old male Maltese terrier weighing 1.0 kg with a heart murmur is presented. A right SVA and a ventricular septal defect (VSD) were diagnosed by echocardiography and cardiac catheterization. The dog died due to a worsening of his condition. The necropsy revealed the sinus of Valsalva to have a diameter of 7 mm and a VSD hole was on the opposite surface. This report is the first to describe an unruptured SVA in the right coronary cusp of a small dog.