Left ventricular outflow tract to left atrial fistula associated with endocarditis in a dog

A one-year-old, intact male, 28-kg, mixed-breed dog developed neurological episodes consistent with emboli. An acquired III/VI holosystolic heart murm ur was ausculted in the mitral area, and valvular endocarditis with pulmoni c and aortic insufficiency were noted at echocardiographic examination. An abnormal communication (i.e., fistula) between the left ventricular outflow tract (LVOT) and the left atrium adjacent to the mitral valve annulus was noted with Doppler imaging and confirmed with angiography, Infective valvul ar endocarditis was confirmed based on two of three blood cultures being po sitive for Staphylococcus intermedius. In humans, a sequela to infective endocarditis of the aortic or mitral valv e, or both, is rupture of the mitral-aortic intervalvular fibrosa, resultin g in a communication between the LVOT and the left atrium, This is the firs t report of this sequela in the dog.