Since there are few reports on the cardiomyopathy in the English Cocker Spaniel on literature, the present study intends to contribute for the better characterization of its diagnosis as well as to add knowledge for its clinical, electrocardiographic, radiographic and echocardiographic aspects. Twenty Cocker Spaniel dogs with dilated cardiomyopathy were evaluated for electrocardiography, radiography, echocardiography, biochemical serum profiles and arterial pressure determination. The treatment was individualized in the dependence of the gravity of the congestive heart failure. The results confirmed the long assintomatic period of the disease, being the congestive heart failure the terminal event in its evolution due to the continued loss of the myocardial contractile force. The average age of the animals was seven years old. The clinical manifestations were directly related to decrease of the cardiac output. Most of the animals presented a favorable clinical evolution of the congestive heart failure, although, the occurrence of the disease refractory to the therapeutic protocol was identified in those animals with severe biventricular enlargement in the radiographic exam, abrupt appearance of atrial tachyarrhythmias and accentuated reduction of the contractile function in the echocardiography. The electrocardiography represented the best exam to differentiate the cardiomyopathy of the large breeds from the medium ones. Most of the animals revealed variations of the sinusal rhythm, being the supraventricular arrhythmias observed in the animals with important increases of the atrial chambers, representing those of poor prognostic. The increase on the width of R wave, the largest duration of QRS complex and the largest depth of the Q wave, in the derivation II, constituted good indicators for its diagnosis. A positive correlation between the electrocardiographic and echocardiographic results was only observed in relation to the duration of QRS complex. The ventricular function presented mean values of 19%, and lower values (less than 12%) were observed in five animals, showing a severe contractive disfunction. Nevertheless, the long survival of one of these animals indicated the low reliability of the ejection fraction index as the most important factor in determining of the prognosis.
Cocker Spaniel Inglês; heart; dilated cardiomyopathy