The aim of this study was to conduct Doppler echocardiography on healthy free-ranging anteaters (Myrmecophaga tridactyla) and to evaluate the relationship between echocardiographic parameters of diagnostic importance and animal body weight (BW). This work utilized 8 anesthetized adult animals and 4 manually restrained pups. The echocardiographic examinations were performed with the animal in left lateral recumbency. The echocardiographic scans were directed toward the parasternal window. Four cuts of the cardiac silhouette were conducted, two longitudinal and two transverse, to evaluate the systolic and diastolic cardiac parameters. This study recorded the following parameters: interventricular septum (IVS), left ventricular internal diameter (LVID), left ventricular posterior wall (LVPW), ejection fraction (EF), shortening fraction (SF), aortic valve diameter (AOD), and left atrial diameter (LAD). The BW data (kg) of each giant anteater were paired with their respective echocardiographic data. These data were analyzed using correlation and linear regression modeling to assess the extent of the associations between the variables and their reliability. The same associations were analyzed with canine data to compare and determine the possibility of extrapolating the findings between dogs and anteaters. The echocardiographic parameters obtained using M-mode ultrasound from the short-axis transverse sections were adjusted to the left parasternal window because of the difficulty in analyzing them in the right parasternal window. The correlations between the echocardiographic parameters and the BW were found to be reliable, indicating that they could potentially be used as a simulation model for anteaters when an adequate number of animals are included in the analysis. The verification of the echocardiographic values obtained in anteaters utilizing reference intervals for dogs demonstrated acceptable hit rates, although the statistical results were not satisfactory.