Dilated cardiomyopathy has emerged in the literature and news due to recent opinion-based journal articles and public releases from regulatory agencies. Dilated cardiomyopathy is frequently associated with a genetic predisposition in certain breeds of dogs and can also occur secondary to other diseases and nutritional deficiencies. Cardiac dilatation is the thinning of the myocardial walls and especially of the ventricular myocardium, in the vast majority of cases being the natural consequence of the presence over time of the factors causing hypertrophy. Any obstruction in the two circulations increases the pressure and leads to compensatory hypertrophy, then dilation. The most common mechanical causes occur in the lower circulation through various acute pulmonary diseases that prolong into subacute or chronic form. Static disease in the great circulation is represented by arteriosclerosis, atheromatosis, aneurysms, thrombosis, chronic hepatic or renal organopathies. Left or right atrioventricular insufficiency goes through the hypertrophy phase and then reaches dilation. Pathogenetically, there is a weakening, stretching and dystrophy of the myocardial fibers that can occur on all walls if the efforts imposed by infectious diseases, intoxications, deficiencies intervene at the same time, the reserve force of the heart being exhausted. Dilatations of the atria are rapid from the moment when obstacles appear in the atrioventricular transit due to their thin wall. Dilation of the right heart is the second most frequent after global dilation and results in blood stagnation in the spleen and liver (right heart safety valve). Dilation of the left heart occurs last and results in severe hypoxia with worsening of all general signs, including cardiac signs. This study includes a number of 13 dogs with their age ranging between 6 and 14 years, that we’re examined at the University Emergency Hospital Prof. univ. Dr. Alin Bîrțoiu, Bucharest and within a private veterinary clinic in Bucharest. They have a prolonged pre-symptomatic phase of the disease, extending over years. The patient’s echocardiography examen indicates a dilated heart, with thin hiperechoic walls, hypokinesia of the cardiac walls, increased telesystolic and telediastolic volume of the left ventricle and left atrium, reduced contractile substrate and interventricular septum. The aim of this study was the early diagnosis of one of the most common heart diseases in senior dogs - dilated cardiomyopathy characterized by chamber dilatation and myocardial systolic and diastolic dysfunction.