Description
Feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV) are retroviruses causing lifelong immunosuppression in cats. FeLV primarily spreads via oronasal contact with saliva (grooming, shared bowls) and causes acute fever, lymphadenopathy, and lethargy, progressing to chronic anaemia, recurrent infections (stomatitis, upper respiratory disease, skin abscesses), neoplasia (lymphoma, leukaemia), immune-mediated disease, and reproductive failure (abortion, fading kittens).
FIV transmission occurs mainly via bite wounds, leading to acute flu-like illness (fever, lymphadenopathy) followed by an asymptomatic carrier phase (years), then acquired immune deficiency with chronic gingivostomatitis, weight loss, recurrent secondary infections (respiratory, urinary, dermatologic), neurological signs (behaviour changes, seizures), and oral neoplasia.
Diagnosis uses whole blood (EDTA), serum, or plasma for antigen/antibody screening: FeLV snap tests (ELISA) detect p27 antigen in blood/saliva (confirm positives with IFA on bone marrow), while FIV antibody tests (ELISA/Western blot) identify infected cats (kittens retest at 6 months due to maternal antibodies). qPCR on blood or plasma detects proviral DNA/RNA, quantifying viral loads to confirm infection (especially antigen-negative FeLV carriers), stage disease progression, monitor antiretroviral therapy (e.g., AZT for FIV), and distinguish transient viraemia from persistent infection; bone marrow qPCR aids occult FeLV diagnosis.
