Regulation of Calcium Concentration in Primary and Secondary Hyperparathyroidism

The parathyroid gland is probably the simplest endocrine organ in the body. The only cells of clinical significance are the parathyroid or chief cells. The primary signal that these cells listen to is calcium. Primary hyperparathyroidism is due to a parathyroid adenoma. The most common cause of hypercalcemia in veterinary medicine is hypercalcemia of malignancy associated with variety of neoplasms. Secondary hyperparathyroidism is due to a disease process, most commonly associated with renal and nutritional hyperparathyroidism. Primary and secondary hyperparathyroidism are markedly different in their clinical, laboratory, and pathogenic mechanism.