TABLE 19-1.

Diagnostic Assays Available for Feline Panleukopenia

Assay	Specimen Type	Target	Performance
Canine parvovirus fecal antigen ELISA	Feces	Parvoviral antigen	Sensitivity varies with the assay used and the timing of specimen collection. False negatives are common, but a positive result generally indicates infection.
Histopathology	Usually necropsy specimens, especially gastrointestinal tissues	Crypt necrosis with intranuclear inclusions; FPV antigen with IHC or IFA	Can be used for necropsy diagnosis.
Polymerase chain reaction (PCR)	Feces, tissue samples	FPV DNA	Sensitivity and specificity varies depending on assay design. The extent to which attenuated live vaccine virus can be detected after vaccination is not well understood. Because of the high sensitivity of some assays, the significance of a positive result may be difficult to interpret. False-negative results may occur as a result of inhibition of PCR by components of feces.
Fecal electron microscopy	Feces	Virus particles	Not widely available, turnaround time can be slow, and may be expensive. Requires the presence of large amounts of virus.
Virus isolation	Feces, tissues	FPV	Difficult, not widely available. Used primarily as a research tool.

FPV, feline panleukopenia virus; IFA, immunofluorescent antibody; IHC, immunohistochemistry.