Cat Guardians 101

endFIP attention pleasePlease note: This section is intended for pet guardians and for information purposes ONLY. If you have a sick cat, please consult a qualified veterinarian IMMEDIATELY.

The authors exclude all liability whatsoever for any loss or damage arising out of the use of this website or reliance upon its content and STRONGLY advises anybody with veterinary related questions to consult a qualified veterinarian. 

What is Feline Infectious Peritonitis?

Feline Infectious Peritonitis (FIP) is a devastating viral disease of cats that occurs worldwide and can affect many systems of the body. It is a progressive disease which carries a high mortality rate. FIP affects both wild and domestic cats and may be the leading infectious cause of death of cats.

In 1963, American veterinarian Jean Holzworth first described a peritonitis in cats which caused the abdominal cavity to fill up with fluid. The condition appeared to be infectious, hence the name Feline Infectious Peritonitis (FIP). Within a few years, it was recognized that the cause of the disease was a virus, a coronavirus. Feline coronavirus (FCoV) is undoubtedly one of the most poorly understood feline virus, and the disease it causes (FIP) is unquestionably the most feared disease in any multi-cat environment and the most shattering diagnoses for a pet parent to come to terms with.

Most cats infected with FCoV never develop FIP. However, for reasons that we don’t yet fully understand, instead of clearing the FCoV infection, an unfortunate few cats develop the disease.

What causes Feline Infectious Peritonitis?

FIP occurs when the cat reacts inappropriately to feline coronavirus (FCoV) infection, in other words, FIP is an unusual immune response to infection by the feline coronavirus (FCoV). FCoV can be found in the feces of infected cats.

FCoV is a relatively uncommon virus in pet cats allowed access to the outdoors and kept in households of one or two cats, but in situations where there are a lot of cats (i.e., breeding catteries, rescue shelters, hoarding situations, etc.) FCoV is endemic, infecting almost all of the corresponding cat population. Most cats infected with FCoV either show no signs of illness at all or experience mild diarrhea or transient cat flu-like symptoms. FCoV infected litters of kittens tend to be of uneven size, even runty. Some cats and kittens infected with FCoV develop severe diarrhea and very few FCoV infected cats (less than 10%) go on to develop FIP.

Feline coronavirus (FCoV) is shed in the feces. FCoV infection occurs when cats ingest (or inhale) the virus. FCoV is a very contagious virus, and it only takes a speck of cat litter dust from a litter tray previously used by an infected cat for the virus to spread. Therefore, exposure to feces in litter boxes is the most common mode of infection.

importantA positive FCoV test alone is NEVER enough evidence to say that the cat has FIP

The key event in the development of FIP is the infection of the monocyte (a white blood cell) by the feline coronavirus (FCoV). From the moment of infection of the monocyte, the cat’s fate hangs on whether or not that monocyte can contain the virus and eventually defeat it, or whether the virus wins, and begins replicating within the monocyte.
In cats with FIP, the infected monocyte, instead of destroying the virus, becomes its ally: attaching to the lining of a blood vessel and releasing inflammatory factors which attract more white blood cells to the site, which is now a tiny pyogranuloma (an abscess-like swelling).

Watch this video to learn more about how cats become infected with feline coronavirus, the virus which causes FIP.

Watch this video to learn more about how infection of monocytes by FCoV leads to the development of clinical signs of Feline Infectious Peritonitis.

What cats are at risk of developing FIP?
What are the clinical signs of FIP?

How do you reach the FIP diagnosis?
What are the treatment options for FIP?

What can you do to prevent FIP?
Grieving for the loss of your  FIP cat

DISCLAIMER: The use of this website is at your own risk. This website is for information purposes ONLY, and it is NOT meant to replace a consultation with a fully qualified veterinary surgeon (veterinarian). It is NOT intended to be used to diagnose or treat any cat. The creators share their personal experiences, recommendations of treatments, foods, medications, supplements, and products for informative and educational purposes exclusively. The information in this site cannot and should not be used as a basis for diagnosis or choice of treatment. Creators and contributors exclude all liability whatsoever for any loss or damage arising out of use of this site or reliance upon its contents. Furthermore, creators and contributors strongly advise all users to always seek the advice of a qualified veterinarian and to obtain professional advice on the correct regimen for your cat and his or her particular situation. NO responsibility can be accepted.