Prevalence of Type-C Virus and Antibodies in Normal Cats and Cats With Neoplasia

Summary

Cats with suspected neoplasia were bled before euthanasia and a complete necropsy was performed. Samples of different tissues were obtained for electron microscopy and for establishment of cell cultures. Of these cats, 83 of 122 had some type of neoplasia; the remainder had other non-neoplastic diseases. Sera from 102 of the cats were examined by the indirect fluorescent antibody (IFA) procedure for antibodies against feline leukemia virus (FeLV). The sera from 41% of the cats with non-neoplastic diseases were positive, whereas sera from 33% of the cats with neoplastic diseases were positive. In contrast, 5% of “normal” cat sera was positive in the IFA procedure against FeLV. Examination of tissues by electron microscopy showed type-C virus in 58% of the cats with neoplasia and in 44% of those with non-neoplastic diseases. None of the tissues obtained from 11 “normal” cats was positive for type-C virus. Continuous cell cultures were established from involved tissues of 10 of the cats, and 6 of the 10 continued to produce type-C virus in vitro. Cell-free extracts from some tumors and from some of the cell cultures producing type-C virus produced neoplasia when inoculated into fetal or newborn kittens.