Erythroid Hypoplasia in Cats Inoculated With Feline Leukemia Virus 2

Abstract

Severe anemia was induced in 13 of 15 cats inoculated at birth with preparations of the KT feline leukemia virus (FeLV). The disease was transmitted through 3 serial passages. The survival period for the affected cats was 49–179 days. Serial examination of blood and bone marrow revealed progressive, nonregenerative anemia associated with profound erythroid hypoplasia in the marrow. In the first FeLV passage, 2 of 7 anemic cats had concurrent focal lymphosarcoma confined to the marrow. No neoplasia was evident in the cats that developed anemia in the second and third serial passages. Serial blood smears of 3 inoculated cats were examined for FeLV group-specific antigens. FeLV antigens were detected in leukocytes of cats 5 weeks post inoculation, which was 4 weeks before the onset of anemia. The cats remained FeLV positive throughout the anemic period.