Secondary hypoparathyroidism to omeprazole prolonged use in a dog: case report

ABSTRACT Primary or secondary hypoparathyroidism is a rare disease in dogs caused by the decreased secretion of parathormone from the parathyroid glands, leading to clinical signs of hypocalcemia. Omeprazole has been increasingly used in veterinary medicine in order to reduce the production of cerebrospinal fluid, but there are few reports of side effects related to its chronic use. We report a case of a four-year-old male Yorkshire terrier with clinical signs of pain, calcification in the pelvis and renal diverticulum. According to the owner, the dog had been receiving omeprazole for over 2 years because of the history of hydrocephalus. Hematological exams revealed hypochromic microcytic anemia, hypokalemia, hyperphosphatemia, hypocalcemia, hypomagnesemia besides hypercalciuria. The determination of serum parathyroid hormone concentrations confirmed hypoparathyroidism. After interrupting omeprazole, the altered features on the exams returned to normal values, confirming that the cause of hypoparathyroidism was the chronic use of the drug.