Disease of the thyroid gland has been known for thousands of years. Both neoplastic and nonneoplastic diseases affect the thyroid. This is the first report, as far as we are aware, of pathological lesions from the thyroid gland of sheep. The survey was conducted from March 2001 to March 2002.Thyroid glands were collected from 100 sheep during routine slaughter and inspection in Tabriz slaughterhouse, Iran. Thyroid glands were assessed histopathologically. Of all 100 thyroids examined, 33 showed various lesions. Of total samples, 4 (4%) showed colloid goiter, 27 (27%) showed hyperplastic goiter. Of total samples 2(2%) showed lymphocytic (immune-mediated) thyroiditis
