EFFECT OF MITHRAMYCIN ON HYPERCALCEMIA IN DOGS

A single, intravenous dose of mithramycin (25 mug/kg body weight) was successfully used to reduce serum total and ionized calcium concentrat ions in five of eight dogs with neoplasia-associated hypercalcemia and in one dog with vitamin D toxicity. The clinical effectiveness was ma ximal one to two days after administration. There was no significant h epatic toxicity, and bone marrow, renal, or gastrointestinal toxicitie s were minimal. In contrast, a higher dose (100 mug/kg body weight) of mithramycin induced severe hepatic necrosis and death in two dogs wit h cancer-associated hypercalcemia.