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.