Serum erythropoietin changes in cats with feline leukemia virus-induced erythroid aplasia.

Erythropoietin concentrations were increased significantly (p less than 0.025) in nine cats with natural feline leukemia virus infection and associated erythroid aplasia compared to six clinically normal cats. Adult cats experimentally inoculated with the Kawakami-Theilen isolate of feline leukemia virus developed a progressive simultaneous increase in erythropoietin activity and decrease in packed cell volume. These findings indicate that erythroid aplasia associated with feline leukemia virus infection is not caused by a failure in erythropoietin production.