The Evaluation of Thyroid Gland Volume in the Foals by Ultrasonography

Ultrasonography of the thyroid gland is a non-invasive method for evaluating its size, which can be used to examine the initial increase in the volume of the gland in live foals. In this study, the ultrasonography, as a standard method, was used to measure the extent of the thyroid gland. For this purpose, ۱۴ Kurdish foals were selected which the age of those was between ۲ and ۹۰ days. In each of the foals, the size of the thyroid gland was measured with ultrasonographic method of three standardized axes and total volume (VSON) was calculated using the formula for an ellipsoid body. Variability of ultrasonographic measurements was dependent on side and axis, and ranged between ۳.۰۴-۷.۳۵ percent. The relationship between body weight and thyroid volume was significant. Generally, the thyroid size of the foals can be calculated by evaluating ultrasonography in three axes and comparing with predicted values based on body weight.