ULTRASONOGRAPHY OF THE UMBILICAL STRUCTURES IN CLINICALLY NORMAL CALVES

The umbilical stalk, vein, and arteries, urachal region, and urinary b ladder of 9 healthy Holstein calves were scanned ultrasonographically at weekly intervals from 1 day to 3 weeks of age. Four additional calv es of representative ages, 1 day, 1 week, 2 weeks, and 3 weeks were eu thanatized after ultrasonographic evaluation of the umbilical structur es. Umbilical structures from these 4 calves were dissected, photograp hed, and examined histologically to ensure normalcy. These gross speci mens were correlated with the ultrasonographic images and compared wit h serial ultrasonograms of 3 calves. The ultrasonographic scanning tec hnique and the appearance of normal umbilical stalk, arteries, and vei n, and urachus in calves were different from those described for foals . The umbilical vein of calves was scanned from the umbilical stalk to the liver along the right abdominal wall. Two veins, which merged wit hin the body wall, were identified within the stalk. Umbilical arterie s were not found within the umbilical stalk; they ended abruptly near the apex of the urinary bladder. A urachal remnant was not identified in any of the calves. A range of normal values for measurement of the umbilical stalk, umbilical arteries, and umbilical vein at 3 sites was determined. The described ultrasonographic appearance and measurement s of the normal Holstein calf umbilicus may be used as a reference for evaluation of calves with internal umbilical abnormalities.