wildlife and zoo assay data sheet
Feline infectious peritonitis (FIP)
virus and feline enteric coronavirus (FECV, aka FCoV)
- Qualitative detection of FIP virus by reverse transcription coupled
real time polymerase chain reaction.
- Qualitative detection of FECV by reverse transcription coupled real
time polymerase chain reaction.
Feline infectious peritonitis (FIP) is caused by a coronavirus that
can infect any cat, but especially young cats and very old cats (14 yr
and up). The FIP virus (FIPV) is genetically very similar to another
coronavirus, feline enteric corona virus (FECV), which causes a
transient, usually mild, self-limiting diarrhea. FECV infection often
persists in apparently healthy animals,which shed the virus in
their feces. Natural infection occurs via the faecal-oral route. FECV
infection appears to be mainly restricted to the intestinal tract
(Chang, 2010; Vogel, 2010), where the virus replicates in villous
epithelial cells (Vogel, 2010).
Unlike FECV, FIPV does not spread readily among cats. Instead, it
originates de novo from FECV in individual
animals (Vogel, 2010). Clinical development of FIP is quite complex
and, depending on the status of the animal’s immune system, symptoms
can vary significantly. In some instances, the immune system’s
response to infection may actually worsen clinical signs. Two major
forms of the disease can be recognized. In the effusive form of FIP
there is accumulation of substantial quantities of fluid in body
cavities (abdomen and chest). Some of these animals appear profoundly
"pot-bellied". In the dry form of FIP there is little fluid buildup.
In both forms, clinical signs can be quite variable; virtually any
organ or soft tissue system can become affected, thus mimicking many
diseases. The most common clinical signs are non-specific and include
fluctuating fever, inappetance, lethargy and weight loss. Sometimes,
if the central nervous system is affected, neurological abnormalities
Many apparently healthy cats carry the FECV virus, shedding it
intermittently in feces. Mortality from environmental exposure to FECV
virus (ie from other animals shedding virus) is sporadic, even in a
population of cats where FIP virus carriers are known to be present.
Additionally, most cats with FIP no longer have detectable
intestinal feline coronaviruses (Chang, 2010).
In the past, diagnosis of active FIP was based on a high level of
antibody to the FIP virus along with signs of the disease which may or
may not be specific. However, serology testing
can yield many false negative and false positive results (Addie, 2004).
There are several reasons for this. First, FIPV and FECV are extremely
similar and hence exhibit strong serologic cross reactivity; in fact
cats exposed to other feline coronaviruses may test "positive" or even
"strongly positive” for FIPV by serology. Second, FIPV vaccination may
cause uninfected cats to test positive by serology. Third, some
FIPV-infected cats simply may not develop an immune response. Immune
system components may actually be involved in the progression of the
disease and be "consumed" in the disease process. Or, the disease may
be in the early stages so that there has not yet been enough time to
develop the antibodies. Also, some animals are immune-suppressed from
concurrent diseases such as feline AIDS, so that the immune response
machinery is impaired. Finally, antibody levels fluctuate up and
down, seemingly in random fashion, in both FIPV and FECV infected
cats. No specific pattern has been discernable in this fluctuation, so
a change in antibody titer does not imply an active infection.
In live cats, detection of FIPV by reverse transcription polymerase
chain reaction is regarded as a relatively specific and sensitive
technique for detecting FIPV (Kennedy, 2003). Recent research
indicates that reverse transcription PCR detection
of FIPV in mesenteric lymph node fine needle aspirate samples
or thoracic effusion samples is
predictive of active infection. Since this technique directly
detects the viral nucleic acid, a positive result provides a strong indication of the presence of the
virus. In view of the low rate of false positive results,
reverse transription coupled real time PCR can be a valuable addition
to the diagnostic arsenal for FIP (Simons, 2005).
McLachlan, S.A., Golder, M., Ramsey, I., Jarrett, O. (2004) Evaluation
of an in-practice test for feline coronavirus antibodies. J Feline Med
Surg. Apr 6(2):63-7.
Chang, H.W. et al (2010) Feline infectious
peritonitis: insights into feline coronavirus pathobiogenesis and
epidemiology based on genetic analysis of the viral 3c gene. Journal
of General Virology. 91, 415–420.
Kennedy, M., Kania, S.,
Stylianides, E., Bertschinger, H., Keet, D., van Vuuren, M. (2003)
Detection of feline corona virus infection in southern African non
domestic felids. J Wildlife Dis. Jul 39(3):529-35.
Simons, F.A et
al (2005) A mRNA PCR for the diagnosis of feline infectious
peritonitis. J Virol Methods 124(1-2):111-6.
Vogel, L. et al (2010)
Pathogenic characteristics of persistent feline enteric coronavirus
infection in cats. Vet. Res. 41:71.
0.1 ml mesenteric lymph node fine needle aspirate, or 0.2 ml thoracic effusion
0.2 ml feces, or rectal swab
Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.
For all specimen types, if there will be a delay in shipping, or
during very warm weather, refrigerate specimens until shipped and ship
with a cold pack unless more stringent shipping requirements are
specified. Frozen specimens should be shipped so as to remain frozen
in transit. See
shipping instructions for more information.
Turnaround time: 2 business days
transcription coupled real time PCR
Normal range: Nondetected