Evaluation of a saliva test kit for feline leukemia virus antigen

An enzyme-linked immunosorbent assay (ELISA) test kit for the detection of feline leukemia virus (FeLV) antigen in saliva was evaluated in 150 cats. Saliva and blood samples from all cats were tested for FeLV using the saliva ELISA kit and a plasma ELISA kit, respectively. These results were compared with indirect immunofluorescent antibody (IFA) testing of blood smears also obtained from each cat. The proportion of cats that tested positive were 10%, 7%, and 8% for each test, respectively. Using the IFA test as the gold standard, the saliva FeLV test had a sensitivity of 91.7% and specificity of 97.1%, while the plasma ELISA test had a sensitivity of 91.7% and specificity of 100%.