OBJECTIVES: Volume measurements of the left ventricle are essential part of echocardiographic diagnosis of canine heart diseases. Three-dimensional echocardiography (3DE) has been rarely used in veterinary medicine mainly due to economic limitations. A new technique now allows a fast semi-automatic direct measurement with 3DE, additionally to the calculation of volumes according to reported formulas, as used previously. This new method has proven in human medicine to reveal comparable results to those obtained from the gold standard MRI. MRI is not indicated in dogs suffering from heart failure, because of the necessity of general anesthesia. The aim of this study was to compare results from conventional methods of echocardiography with 3DE. METHODS: End-diastolic and end-systolic standard measurements of the left ventricle were performed in 42 healthy dogs (beagles and dachshunds), including calculation of volume according to Teichholz measurements using M-Mode, calculations of volume using single plane and biplane method of discs (Simpson’s rule) with two-dimensional echocardiography (2DE), and biplane method of discs from multiplane images and the frustum of 3DE, as well as direct volume measurement with 3DE. Agreement between methods was analyzed using a modified Bland-Altman plot. RESULTS: When comparing with the direct 3DE measurement of volume, calculated volumes were slightly underestimated with 3DE, and increasingly underestimated with 2DE. However, the deviations were predictable for the respective dog sizes. Results from M-Mode unpredictably overestimated volume of the left ventricle. CONCLUSIONS: When considering the direct measurement of volume as being the most reliable method, other measurements performed with 3DE resulted in highest consistency. Results obtained with 2DE revealed higher but still predictable deviations, whereas results from M-Mode were highly and unpredictably deviating. Accordingly, 3DE has the potential to become a new standard in dogs in which MRI is not indicated. However, further clinical and economic evaluations are needed in veterinary cardiology.