The parathyroid glands are multiple (generally four) small glands, approximately 1-2mm in length are located about the cranial trachea. Generally, there are two internal glands embedded within the [[Thyroid Gland - Anatomy & Physiology|thyroid Glands]], and two external glands are outside the thyroid tissue. However, all of the parathyroid tissue may be embedded within the thyroid gland itself. In the Horse, there are 'nests' of parathyroid tissue along the neck to the thoracic inlet. | The parathyroid glands are multiple (generally four) small glands, approximately 1-2mm in length are located about the cranial trachea. Generally, there are two internal glands embedded within the [[Thyroid Gland - Anatomy & Physiology|thyroid Glands]], and two external glands are outside the thyroid tissue. However, all of the parathyroid tissue may be embedded within the thyroid gland itself. In the Horse, there are 'nests' of parathyroid tissue along the neck to the thoracic inlet. |