Arterial vascularization of the pig thyroid gland: an anatomical identification and variations.

The thyroid gland is a highly vascularized organ in vertebrates. However, the information on the vascular pattern of this gland in pigs remains limited. This study elucidates the morphoanatomy and arterial supply of the gland in three breeds: Landrace (L), Large White (W), and Crossbreed (LWD). Two hundred twelve pigs were used and dissected to observe the arteries supplying blood to the gland. As a result, the gland was classified into three types based on its appearance: pear-shaped, butterfly-shaped, or partially separated. Moreover, the arteries supplying the gland were observed and then compared among breeds. The arterial supply of the thyroid gland on the cranial side consisted of branches from the cranial laryngeal artery, cranial thyroid artery, superficial cervical artery, and common carotid artery. Otherwise, the caudal side was supplied by the caudal thyroid artery, superficial cervical artery, bicarotid trunk, internal thoracic artery, and external thoracic artery. Furthermore, significant differences were identified between L and LWD, as well as between W and LWD, in the pattern of arterial origin on the cranial right side of the thyroid gland. Similarly, on the left side, significant differences were observed not only between L and W but also between W and LWD. On the caudal side, significant differences were found between L and W, as well as between W and LWD. These anatomical variations provide important insights for research and clinical applications involving the thyroid gland in pigs.