Effect of suramin on serum viral replication in feline leukemia virus-infected pet cats.

Suramin treatments were administered (IV) to 2 healthy adult cats infected with naturally acquired feline leukemia virus. Serum viral infectivity--as assessed by focus induction by the method of Fischinger, using serial serum samples titrated on clone 81 cells--ceased transiently in both cats during treatment with suramin, but returned to significantly high levels approximately 14 days after treatment was stopped. Both cats tested positive for FeLV internal antigens in peripheral blood cells and serum before, during, and after treatment. Both cats tested negative for antibody to feline oncornavirus membrane antigen before, during, and after treatment. The major adverse effects of suramin in the 2 cats were transient vomiting and anorexia.