Molecular detection of Feline leukemia virus in oral, conjunctival and rectal mucosae provides results comparable to detection in blood.

Feline leukemia virus (FeLV) infection causes immunosuppression, degeneration of the hematopoietic system and fatal neoplasms. FeLV transmission occurs mainly by close social contact of infected and susceptible cats. Developing procedures for the diagnosis of feline retroviruses is crucial to reduce negative impacts on cat health and increase the number of animals tested. Blood collection requires physical or chemical restraint and is usually a stressful procedure for cats. Our objective was to evaluate the use of samples obtained from oral, conjunctival and rectal mucosae for the molecular diagnosis of FeLV. Whole blood and oral, conjunctival and rectal swabs were collected from a total of 145 cats. All samples were subjected to the amplification of a fragment of the gag gene of proviral DNA. Compared to blood samples used in this study as a reference, the accuracy for each PCR was 91.72%, 91.23% and 85.50% for samples obtained by oral, conjunctival and rectal swab, respectively. The diagnostic sensitivity and specificity were 86.11% and 97.26% for the oral swab, 90% and 92.59% for the conjunctival swab, and 74.24% and 95.77% for the rectal swabs, respectively. Kappa values for oral, conjunctival and rectal swabs were 0.834, 0.824 and 0.705, respectively. The diagnosis of these samples showed the presence of proviral DNA of FeLV in oral and conjunctival mucosae. In conclusion, mucosal samples for the molecular diagnosis of FeLV are an excellent alternative to venipuncture and can be safely used. It is faster, less laborious, less expensive and well received by the animal.