RUPTURE OF THE LEFT AORTIC SINUS INTO THE PULMONARY-ARTERY IN A DALMATIAN DOG

An 18-month-old male Dalmatian dog was presented for veterinary evalua tion after the pet owner observed a sudden onset of weakness. An acqui red continuous cardiac murmur was detected on physical examination, Tw o-dimensional echocardiographic examination revealed structural abnorm alities of the proximal aorta and pulmonic valve, Doppler echocardiogr aphic studies and cardiac catheterization demonstrated the presence of a proximal aorticopulmonary shunt. A diagnosis of left aortic sinus r upture and aorticopulmonary fistula was made. Antemortem diagnosis of aortic sinus rupture in the dog has not, to our knowledge, been report ed previously. The anatomical variant of left aortic sinus rupture res ulting in the development of a fistula from the aorta to the main pulm onary artery is, apparently, uncommon in all species.