Persistent Hypercalcemia and Hyperparathyroidism in a Horse

• Main Authors: Claudia Cruz Villagrán, Nicholas Frank, James Schumacher, Danielle Reel
• Format: Article
• Language: English
• Published: Hindawi Limited 2014-01-01
• Series: Case Reports in Veterinary Medicine
• Online Access: http://dx.doi.org/10.1155/2014/465425

A 27-year-old, American Quarter Horse gelding was evaluated for anorexia, lethargy, a swelling on the right, cranial aspect of the neck, and signs of esophageal obstruction. Serum biochemical analyses revealed hypophosphatemia, total and ionized hypercalcemia, and hemoconcentration. Sonographic examination of the neck revealed a 1.7 cm diameter mass within the right lobe of the thyroid. The serum concentration of intact parathyroid hormone (iPTH) was increased. The right lobe of the thyroid was excised with the horse sedated. The mass within that lobe was determined, by histological examination, to be a parathyroid adenoma. Despite excision of the mass, serial blood analyses revealed persistent hypercalcemia, hypophosphatemia, and increased iPTH. Anorexia and lethargy resolved, and follow-up communication with the owner and referring veterinarian one year later indicated that the horse was clinically stable.