For the evaluation of the cardiovascular system, methods of diagnostic testing, such as chest X-ray and electrocardiogram, play an important role in identifying pathologies and the disclosure of possible changes that may manifest itself, thereby establishing prognosis, and in a better direction therapeutic conduct to be adopted. The aim this research, to evaluate cardiac electrophysiology, and the radiographic anatomy of the heart of the breed pit bull dogs in the city of Patos, Paraíba, at different ages. The experiment was conducted in dependencies of the Veterinary Hospital (HV / CSTR / UFCG), where 17 dogs were used to breed pit bull, previously divided into two groups: GJ represented by eight animals aged 6-10 months and GA, with 9 animals, ranging in age from 1-6 years. The animals were subjected to the evaluation of radiologic and electrocardiographic parameters. The electrocardiogram parameters analyzed were heart rate (HR),the waves P (ms and mV), R (mV), QRS complex, and QT(ms) and RR(ms) intervals. To radiographic evaluation the cardiac silhouette was analyzed by cardiac spine addition (CSA). The numeric data were submitted to Analyses of Variance (ANOVA) followed the paired "t" of Student test (p < 0,05). Results obtained in the research concerned, it was possible to observe that the groups behaved was relatively homogeneous, being observed significant variations between groups only in relation to heart rate and electrocardiogram segment RR (MS), and expected those differences directly related to metabolism separated from young animals. Regarding the cardiac silhouette was observed SVC slight elevation. It is therefore concluded that the electrocardiographic parameters of the breed pit bull dogs are in accordance with the standards established for the dogs and that the cardiac silhouette may present with a size greater than that recorded in the literature.