Introduction: Left atrial remodeling (LA) in humans is closely associated with increased mortality rates and foci of arrhythmias. Human cardiology guidelines demonstrate the benefits of using atrial volume in staging heart disease. However, in Veterinary Medicine the parameters for determining the atrial dimensions are not completely elucidated. Goal: This study (CEUA/UFPI, N. 652/2020) aimed to study 50 healthy dogs submitted to echocardiographic examination to define the left atrial volume (LAV) indexed to the body area surface, comparing it to traditional methods already established in Veterinary Medicine. Electrocardiographic examination was performed to compare the duration of the P wave with the atrial volume variables. Results and Discussion: The means of the variables studied were: 1) Biplane Volume (mL) AE of 6.76±4.56; 2) LA volume (mL/Kg) of 0.554±0.179; 3) LA volume indexed to the body area surface (mL/m2) of 13.28±5.26; 4) Ae/Ao ratio of 1.36±0.19; 5) Wave Speed E of 72.41±18.10; 6) E/E' ratio of 14.11±5.43; 9) P-wave duration of 43.36±3.77ms. Both the Biplane Volume (mL) AE (r=0.88) and the AE volume (mL/Kg) (r=0.78) showed a high correlation with the indexed AE Volume. Mitral E wave velocity (r=0.35); E/E' ratio (r=o,31); E/IVRT (r=0.31), variables that signal changes in ventricular filling, showed moderate correlations. The volume of the indexed LA was superior to measures such as the left atrium/aorta ratio and other traditional variables. Conclusions: The partial results so far show that Volume AE indexed to body weight, even using animals of varying ages in the same group, is a promising and more accurate method, which can be used in Veterinary Medicine, as already happens in human cardiology.