Secondary erythrocytosis associated with high plasma erythropoietin concentrations in a dog with cecal leiomyosarcoma.

A 14-year-old mixed-breed dog was examined because of severe absolute erythrocytosis (PCV, 70%). Plasma erythropoietin (EPO) concentration was consistently high, even though results of arterial blood gas analyses were normal. Radiography, ultrasonography, urinalysis, and serum biochemical analyses did not reveal any cardiac, pulmonary, or renal abnormalities that could cause the erythrocytosis, and erythrocytosis secondary to inappropriate EPO secretion was diagnosed.