M-MODE ECHOCARDIOGRAPHIC DIAGNOSIS OF DILATED CARDIOMYOPATHY IN GIANTBREED DOGS

M-mode echocardiograms were recorded from 62 giant breed dogs without historical, clinical electrocardiographic and roentgenologic signs of heart disease, from six dogs with asymptomatic dilated cardiomyopathy (DCM, NYHA class I), and 13 dogs with symptomatic DCM (NYHA class III- IV). There was a general trend that several echocardiographic paramete rs were significantly different in control Great Danes as compared to Newfoundlands and Irish Wolfhounds. There were substantial differences in left ventricular size both in systole and diastole and in systolic indices of the left ventricle between the control group, the asymptom atic dogs and symptomatic dogs with DCM (P = 0.0001). There was also a significant decrease in the interventricular septum thickness (P = 0. 0001) and left ventricular free wall thickness in systole (P = 0.002) and diastole (P = 0.005) between the three groups. Furthermore, the le ft atrial/aortic ratio was significantly different between the three g roups (P = 0.0001). It was concluded that this study established echoc ardiographic reference values in giant breed dogs which may be useful in the study of heart diseases in giant breed dogs.