Feline coronavirus QRT-PCR and FIP
Feline coronavirus (FCoV) is a large single-stranded RNA virus which is very stable and can survive for many weeks in the environment. Infection with FCoV is very common in cats, particularly in multi-cat households, but only a small proportion of FCoV infected cats will develop feline infectious peritonitis (FIP), which is usually fatal. Many cats infected with FCoV show no clinical signs of infection, whilst others develop transient diarrhoea and/or vomiting due to FCoV primarily remaining within the enteric system; a few cats go on to develop FIP due to extensive systemic spread of the virus.
Assays to detect FCoV infection include serology (to detect antibodies against the virus that are present in the blood) and reverse transcription PCR (RT-PCR), which amplifies FCoV in the blood. However, these methods will only indicate that a cat has been, or is infected with FCoV, they WILL NOT tell you if a cat has FIP because neither method can distinguish cats with FIP from those infected with FCoV. It is important to appreciate this when interpreting test results. Although some laboratories are offering RT-PCR for the detection of FCoV, more research is required to validate how useful this test is in the diagnosis of FIP. The design of the RT-PCR assay is very important as some published FCoV assays have been found to also amplify cat genomic DNA, which obviously produces unreliable results. The Molecular Diagnostic Unit is therefore currently investigating the use of a newly designed quantitative RT-PCR (QRT-PCR) assay in cats with and without FIP to determine its usefulness before offering it commercially. It is hoped that this assay will be useful for the diagnosis of FIP when run on tissues or effusion samples, and that detection of FCoV in faeces may be helpful for multi-cat households to identify cats shedding the virus.
For more information about the QPCR diagnostic assays offered please see our list of publications