An abattoir study of thyroid histopathologic lesions and serum thyroid hormones in ewes and their fetuses in hot and cold seasons in Ahvaz

The aims of this study were to investigate the prevalence of histopathologic lesions of thyroid gland and respective thyroid hormones changes in ewes and their fetuses in hot and cold seasons at the Ahvaz abattoir. The blood and thyroid samples were taken from 29 pregnant ewes and their fetuses at the end of cold season (March) and 25 ewes and their fetuses at the end of hot season (September - October). Tissue samples were subjected to histopathological examination and ELISA procedure was used for detection of T3 and T4 levels. The results showed high prevalence of thyroid lesions in ewes and their fetuses. The observed histopathological lesions included parenchymal cyst, follicular hyperplasia, follicular degeneration, hemorrhagia, inflammation and colloid goiter in the ewes, and parenchymal cyst, hyperemia and follicular degeneration in the fetuses. The hot and cold seasons had not any effect on thyroid lesions in ewes and their fetuses. There was no difference of T3 and T4 in ewes and their fetuses between hot and cold seasons. Also, the results showed that the thyroid lesions had no effect on ewes T3 and T4 levels, but significant increase in the serum concentration of these hormones was noticed in the fetuses with thyroid lesions.