Early detection of FIV can aid in maintaining the health of an infected cat and can help prevent the spread of the disease.  A positive test does not necessarily indicate a poor prognosis but an opportunity to effectively manage the disease long term. 


A diagnosis is based on patient history, clinical signs and antibody testing.  Hematological and biochemical findings in patients with FIV can be complicated by concurrent secondary infections.  Generally, a blood panel will show a neutropenia, thrombocytopenia and a non-regenerative anemia.  In some cats a monocytosis and a lymphocytosis may also be observed (11).  Biochemical abnormalities may include increased total protein (hyperglobulinemia) and azotemia (6).  Bone marrow aspirates may show bone marrow arrest, lymphoma or leukemia.  During the early asymptomatic phase of infection, CBC and biochemical analyses are often normal (11). 


In practice, FIV antibodies can be detected using an ELISA snap test on cat serum, plasma or whole blood samples.  False positives are common with the snap test largely do to increases in vaccine use as the test cannot distinguish between vaccine antibody and antibody against the actual virus.  Cats that test positive in the clinic should be confirmed positive by sending away lab samples to be tested with PCR or Western blot to rule out false positive results (6).  Cats in the acute/early phase of infection may be antibody negative as they have not yet mounted an antibody response to the virus.  These cats should be retested in six to eight weeks.  Most cats develop a detectable antibody response within eight weeks of initial infection.  It should also be noted that animals entering the terminal phase of the disease my loose any detectable antibody in their body due to the debilitating effects of the disease on the immune system (6).

Snap Test


Kittens can have colostrum derived antibody in their serum for up to several months post-partum.  If a kitten tests positive for FIV antibodies and is less than six months old, retest the animal every 60 days until the result is negative.  If antibody against FIV persists past 6 months the kitten is likely infected with FIV (11). 


Testing for FIV is indicated in the following situations: