Testing your cat for FIP is a personal decision. We do not suggest that you don't test, but, make absolutely certain that the test actually diagnoses FIP. The blood test (Coronavirus serology test) usually used in Nova Scotia is many times called a "FIP" test. It is a test for Feline coronaviruses (FCoV) .
The Cat Group,United Kingdom, is a collection of professional organisations dedicated to feline welfare through the development and promotion of policies and recommendations on the care and keeping of all cats.
"The Coronavirus serology test is a laboratory test that detects antibodies in a cat's blood sample against feline coronavirus (FCoV). However, this blood test does not have the ability to distinguish between different strains of FCoV, and cannot differentiate between strains that cause FIP and those more common strains that do not. Additionally, the presence of antibodies does not necessarily imply that the cat is currently infected with FCoV, although in practice it appears that in most antibody positive cats FCoV can be found. Although this blood test is often used as part of the investigation of a suspected case of FIP, it is not particularly helpful as a very large number of perfectly healthy cats have positive test results reflecting the high level of exposure to FCoV in the cat population (most strains being unlikely to cause any significant disease)."
"FIP is the term for clinical disease associated with feline coronavirus infection. The common benign form of feline coronavirus is referred to as FECV (feline enteric coronavirus). When FECV has mutated into a disease-causing form, it is then referred to as FIPV (feline infectious peritonitis virus). Feline coronaviruses in general are referred to as FCoV. FECV is a very common, highly infectious feline virus. The majority of cats with FECV (about 90% or more) remain healthy. But in a small number of cases, FECV infection is the first step in a chain of events leading to FIP.
The fact remains that we have no screening test for FIP in well cats. Neither do we have a foolproof way to diagnose FIP in a sick cat. The gold standard remains a biopsy or findings at necropsy (death)."
Arnold Plotnick MS, DVM, ACVIM, ABVP, Manhattan Cat Specialists, New York City
"In conclusion, the only way to definitively diagnose FIP is by biopsy, or by detection of coronavirus in cells from body cavity fluid of affected cats. There is no simple blood test that can make the diagnosis, and I shudder to think of how many cats have been euthanized unnecessarily due to a mistaken belief amongst many veterinarians that a positive antibody test is diagnostic for FIP."