As aging goes on, adaptive capability decreases, the individuals become more susceptible to a lot of pathologies, mainly those that involve cardiovascular system, being the electrocardiographical test an essential diagnostic tool. Precordial derivatives are used to confirm the data obtained from other derivatives like cardiac enlargement, congenital heart defects, cardiac blocks or attacks, or to make more evident the P wave, helping to find the arrhythmias diagnosis. In human beings, precordial derivatives are very important to diagnose of diseases, because their normal values are already standardized, however, in pet practice, those values are not determined yet. The aim of this work was to establish electrocardiograph precordial derivatives (V2, V4, V5, V6) in canines older that 9 years old clinically health (n = 60).