[Feasibility of sonography in the diagnosis of congenital heart diseases in dogs].

In ultrasound examination of the heart it is useful to combine the following techniques: echocardiography (in 2D and M-mode) gives information about morphology and motion of the heart. By using Doppler echocardiography (black and white or preferably colour) it is possible to evaluate bloodstreams and with contrast echocardiography shunts in the heart can be demonstrated. In our study (1994-1996) the following congenital heart defects were the most common in dogs: subaortic stenosis (SAS, 41%), pulmonic stenosis (PS, 19%), patent ductus arteriosus (PDA, 11%) and the combination of subaortic stenosis with pulmonic stenosis (11%). Echocardiography allows the morphologic evaluation of the primary defect in detail, for example the differentiation between aortic valve stenosis and subaortic stenosis. However the exact identification of the patent ductus arterious and of the morphology in pulmonic stenosis can remain difficult, especially in patients showing dyspnoe. In heart sonography quantitative measurements are available to graduate the defects, but guidelines for these measurements are not yet defined. The demonstration of secondary and combined defects, which are important for therapy is easily possible with heart ultrasound examination. Secondary insufficiencies are often seen at the mitral valve because of primary subaortic stenosis or patent ductus arteriosus and at the tricuspid valve because of pulmonic stenosis. For differentiation of combined heart defects (SAS with PS; SAS with PDA; PS with atrium septum defect) heart ultrasound is extremely valuable.