DIAGNOSTIC AND THERAPEUTIC CONSIDERATIONS IN A HYPERCALCEMIC DOG WITHMULTIPLE ENDOCRINE NEOPLASIA

Hypercalcemia was found in a dog examined for episodic weakness and di sorientation. A right adrenal mass identified on abdominal ultrasonogr aphic examination was diagnosed as a pheochromocytoma based on increas ed 1231-metaiodobenzylguanidine uptake and characteristic histopatholo gical features. Serum intact parathyroid hormone (iPTH), total serum c alcium, and ionized serum calcium were increased prior to surgery. Alt hough both total and ionized serum calcium concentrations decreased to within normal reference ranges following surgery through postoperativ e day 17, subsequent high concentrations with increased serum iPTH con centrations confirmed concurrent primary hyperparathyroidism. A right parathyroid tumor was suspected based on a technetium-99m-sestamibi (9 9m Tc-sestamibi) scan.