ABSTRACT
Retroviruses are RNA viruses that, after entering the cell, make a DNA copy, which is subsequently integrated into the infected cell's genome. Feline leukemia virus (FeLV) is a common retrovirus that infects cats, and has been studied extensively for many decades. It has three genes—gag, pol, and env—which encode the viral structural proteins and the necessary enzymes. FeLV-infected cats can develop a variety of clinical syndromes, including co-infections, immune suppression, anemia, and tumor formation. The chapter presents the case of Sinbad. Sinbad is an approximately two-year-old spayed female cat, who was formerly a stray and was adopted by a family several months ago. Her vaccination status is unknown. On the basis of the physical examination and the results of the diagnostic tests, Sinbad was diagnosed with FeLV infection with a nonregenerative anemia and thoracic effusion. Since diagnosis of FeLV depends on detection of virus antigen, vaccination for FeLV does not complicate the interpretation of the FeLV enzyme-linked immunosorbent assay.
