Feline panleukopenia can be diagnosed directly by isolation of the virus from blood or faeces
in cultures of CRFK or Mya 1 cells (Miyazawa et al., 1999) and by the demonstration of
haemagglutination of porcine erythrocytes (Goto, 1975). However, these methods are now
rarely used for routine diagnosis.
In practice, FPV antigen detection in faeces is usually carried out using commercially
available latex agglutination or immunochromatographic tests (Veijalainen et al., 1986; Addie
et al., 1998). These tests have an acceptable sensitivity and specificity when compared to
reference methods (Neuerer et al., 2006, in press). Tests marketed for the detection of FPV
antigen as well as those for detecting canine parvovirus antigen may be used to diagnose FPV
in faeces.
Diagnosis by electron microscopy has lost its importance due to more rapid and automated
alternatives. Specialised laboratories offer PCR-based test on whole blood or faeces. Whole
blood is recommended in cats without diarrhoea or when no faecal samples are available
(Schunck et al., 1995; Ryser-Degiorgis et al., 2005). The analytical sensitivity of the antigen
tests can be compromised by the presence of antibodies which may bind the viral epitopes and
therefore render them inaccessible to the monoclonal antibodies in the test kit (Lutz et al.,
1995).
Antibodies to FPV can also be detected by ELISA (Fiscus et al., 1985) or indirect
immunofluorescence (Hofmann-Lehmann et al., 1996). However, the use of an antibody test
is of limited value, because serological tests do not differentiate between infection- and
vaccination-induced antibodies (Fiscus et al., 1985). The mere presence of antibodies is taken
as proof of protection against panleukopenia under field conditions (Lappin et al., 2002).