Effects of growth on functional and morphological echocardiographic variables in Friesian calves

For echocardiography to become a reliable tool for the diagnosis, monitoring and prognosis of cardiac diseases in cattle, it is necessary to determine normal values of echocardiographic variables and their changes during the growth of healthy animals. In this study, 53 echocardiographic protocols were collected from 17 healthy Friesian calves during their period of growth. The protocol consisted of the measurement or calculation of 10 dimensional and six functional variables from M-mode long axis views of the heart. The relationships between these variables and age, body-weight and body surface area were analysed. Most of the dimensional parameters increased significantly with body size and were best predicted by an allometric regression. However, the functional indices did not change with growth, and the normal values obtained in this study may be applied to calves of any body weight.