FIP, or Feline Infectious Peritonitis, is an often fatal condition that affects the cat population worldwide, and yet you might not even know about it. This virus falls under the family of viruses Coronavirus (yes, the same group of viruses that caused a worldwide pandemic). But this virus is unique to cats and does not affect humans.
The condition is mostly seen in younger cats, mostly between 3 months and 2 years of age; however, any age group may be affected. It also seems to affect purebred cats more often and thrives in areas where there are numerous cats or in multi-cat households.
FIP: possible causes
Cats pick up the FIP virus in numerous ways, the most common being ingestion of the virus from the surroundings or even through the air from nearby cats that are harbouring the virus. Fortunately, this virus is not passed from queen mother cats to their kittens; the kittens, however, may become infected if they are kept in unhygienic environments for prolonged periods.
Stressful situations, such as rehoming, major renovation work on your home for a new baby in the house, may also increase the chance of your cat developing the disease. Unfortunately, cats that have been diagnosed (or undiagnosed cats) with Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV) may also be more likely to develop life-threatening FIP infections.
In reality, most cats are exposed to the virus at some point but do not develop FIP.
FIP: why do some get it and others not?
This virus mutates slightly in individual cats, and it is these slight mutations that cause illness. The affected cat’s immune system is triggered, causing a slightly abnormal response, which causes the illness.
There are 3 different forms of this virus:
• A dry form which may go unnoticed until terminal stages. It is most often seen as lumps and bumps (nodules) developing in the cat’s abdomen.
• The wet form may manifest as fluid accumulation in the cat’s abdomen and around the heart and lungs.
• The mixed form is a combination of the two. Initial symptoms include depression, lethargy, loss of appetite, weight loss, persistent fever despite multiple treatments at the vet, difficulty breathing or shallow and rapid breathing, being off balance, vision loss, and sometimes diarrhoea .
How FIP is diagnosed
A diagnosis can be quite a challenge for your vet. This (if any of the above-mentioned signs are noted) usually involves a battery of tests including blood tests, full blood counts, ultrasound or X-rays and a fluid sample obtained from the abdomen (if present). This sample can often be used to isolate the virus in the laboratory. Unfortunately, at times the test results will yield a negative result, yet the cause for these clinical signs may still be FIP. If the test result is positive, it strongly suggests FIP. A sure way to exclude FIP is to have a blood sample analysed for an immune response (antibodies). If this test is negative, we know that the cat probably does not suffer from FIP, and other causes of the symptoms should be investigated. It the test is positive, it unfortunately only means that the cat has been exposed to the virus (even the unmutated form), so it does not prove FIP. Thus, one single test may not be enough, and your veterinarian may need to run multiple tests to try and find an accurate answer. FIP is often a presumed diagnosis, taking into account the results of all of these tests.
Other diseases that may look like FIP include: various cancers (especially abdominal cancers in cats), liver disease, heart failure and other infectious causes (including FIV).
Treatment options
The treatment of FIP in cats includes draining fluid from abdomen and/or chest to make them more comfortable, cortisone treatment (which may be lifelong), antiviral drugs and immune stimulating drugs.
Life expectancy with FIP is unfortunately very short. It may range from only a few days from when first clinical signs are seen, to a few months (however this is very rare).
There may, however, be a light at the end of the tunnel. A new pharmaceutical drug, called Remdesivir, is showing a lot of promise of extending the life of affected cats and improving their quality of life. The success of FIP treatment starts with early detection, accurate diagnosis, and appropriate, aggressive treatment.
