Feline Infectious Peritonitis (FIP)
There is no known cure and no reliable test for FIP, this horrible disease claims cats of every breed, it is the greatest fear of any breeder and cat owner.  There is so very little known about it, however there are many myths and stories that have become “general knowledge”.
FIP is the mutation of a corona virus that brings about severe symptoms leading to death.  The feline enteric coronavirus is very common and lives in the intestine of many cats that appear healthy.  It mutates very readily and just occasionally this mutation enables the virus to escape from the gut, spreading throughout the body and causing FIP.
Since the symptoms can mimic so many other conditions, vets can reach a diagnose of FIP when they don’t know what’s really wrong with a cat, subsequently as there is no single laboratory test that can definitely diagnose FIP, likewise, no diagnostic procedure can identify which FCoV – infected cats will go on to develop FIP, serology cannot be used to differentiate between FECV and FIPV infections.  Vast amounts of money continue to be spent each year by breeders on FIP testing, in almost all cases, the results are non-interpretable, even by the veterinarians.  However, although infection with feline coronaviruses is clearly commonplace, (80 – some % of all felines in the world carry the corona virus in their system), the prevalence of FIP disease is low, it is estimated that only 1- 3% ever get sick.


Unfortunately, the highly infectious nature of the FECV and our lack of understanding of its evolution to FIPV make elimination of risk virtually impossible. 

There is no generally agreed practical and effective scheme for achieving control as there is for other important infectious agents of cats such as respiratory viruses and FeLV.
FIP losses are thought to be higher among cats that spend their early kittenhood in large multiple cat households such as breeding catteries, and shelters.  Overcrowding and intermingling of kittens, adolescent and older cats are a common feature of such environments and are obvious contributors to other infections of cats.
Some catteries isolate and early wean their kittens Prevention of Coronavirus Infection in kittens, however infection with coronavirus is almost assured once these kittens are reintroduced into the normal environment, such as relocation to new homes, visits to the vet/neutering/spaying, cat shows, etc.  The advantage of a successful isolation and early weaning program results in a delay to infection to 16 weeks of age or older.  This is the time when the immune system begins to attain adult levels of activity and when kittens become more resistant to clinical disease of all sorts, including FIP.  Kittens in the 8-12 week age range are just starting to become immunocompetent, near adult levels of immunity are not achieved until 16 weeks and later.  Most kittens are exposed to FECV, at an age when they are not fully immunocompetent.  If infection to FECV were to be delayed for several more weeks or months, the likelihood of the FIPV mutant taking hold should hopefully be greatly decreased, also kittens retained by breeders for future breeding purpose have the chance for their immune systems to mature giving some of the potential stresses of early life such as vaccination the time to pass before introducing them to the rest of the colony.
  Early weaning in isolation also contributes to the control of other infectious agents, cats are known to be secret carriers of many problems however healthy they appear, these problems they can pass on to their kittens. 
Catteries contemplating undertaking the isolation and early weaning programme need to be highly experienced in the care of very young kittens, it is not a method for breeders to take on if they cannot dedicate 100% to the kittens care, it’s exspensive and time consuming.  Breeders also need to determine whether it is viable given their facilities/husbandry, whether it will work for them. 
If the kittens are found to be seropositive at 16 weeks of age, the program has failed. 

There is no such thing as a “FIP-negative cattery.”  

It is true that there is currently no cure, or totally effective prevention, but breeders can make FIP a rare event via wise cattery management.

Interpreting Titre Results

The gold-standard test for measurement of antibodies to feline coronavirus (FCoV)

  • Titres of 1:10 or less are considered seronegative
  • Titres 1:40 or greater considered seropositive
  • Titres <1:10 indicate a low likelihood of coronavirus shedding. If the cat is infected they are likely to stop shedding when isolated.
  • Cats with high titres (1:640 or higher) are almost always shedding virus but can stop shedding upon isolation. This can be demonstrated by a drop in their titre to low or undetectable levels.
  • Cats with clinical FIP usually have a high titre (1:640 or higher), although a few cases may show low titres in the terminal stages (particularly in the effusive forms).
  • The higher the titre the greater the specificity and sensitivity of this test for a diagnosis of FIP. The positive predictive index at 1:1600 is 0.94 and the negative predictive index 0.88 (J Vet Int Med 2003:17 781-790)
  • No single test is suitable to confirm a diagnosis of FIP apart from histopathology. Clinical diagnosis of FIP should be based on a wide variety of tests including history, age, number of cats in household, persistent pyrexia and laboratory data including assessment of acute phase proteins, analysis of effusions, haematology and biochemical tests as well as specific serological tests to list a few.