Standard echocardiography is vital for the assessment of cardiac performance in healthy
and diseased animals. Similarly, two-dimensional speckle-tracking echocardiography (2D-STE) is
an advanced echocardiographic technique that is becoming increasingly important for the assessment
of myocardial function. Breeds, age, and body weight (BW) are known to be important factors
affecting the echocardiographic parameters; therefore, the aim of this study was to evaluate the
effect of breed, age, and BW on the echocardiographic parameters in three breeds of clinically
healthy Retrievers. A total of 46 Retrievers, including 16 Flat-coated Retrievers (FR), 16 Golden Retrievers
(GR), and 14 Labrador Retrievers (LR) were included in the study. The comparison of the
breeds revealed significant differences in the LV wall thickness of FR and GR, although further
analysis using MLR showed that the differences were most likely associated with BW, similarly to
the other LV dimensions. Functional parameters, including ejection fraction, fractional shortening,
and left-atrial-to-aortic ratio, were independent of breed, age, and BW. On the other hand, peak
aortic blood flow velocity, trans-mitral rapid ventricular filling flow, and the ratio of trans-mitral
rapid ventricular filling flow to atrial contraction were influenced by age. The 2D-STE-derived radial
and circumferential strain parameters were independent of breed, age, and BW, except for
global strain in the radial direction.