Feline Infectious Peritonitis (FIP)

Feline Infectious Peritonitis (FIP) is a common disease in young cats in HK. The disease  is caused by a virus called corona virus and if it develops into the full blown disease, is fatal.

Most strains of feline corona virus are not too serious, which means that they do not cause disease, and are referred to as feline enteric corona virus. Cats infected with a feline corona virus generally do not show any symptoms during the initial viral infection except for possibly a mild diarrhoea or upper respiratory infection. In a small percent of infected cats (less than 10%),  by a mutation of the virus, the infection progresses into clinical FIP. The virus is then referred to as feline infectious peritonitis virus (FIP). With the assistance of the antibodies that are supposed to protect the cat, white blood cells are infected with virus, and these cells then transport the virus throughout the cat's body. An inflammatory reaction occurs around vessels in the tissues where these infected cells locate, often in the abdomen.

Risk factors for cat:
Any cat that carries the corona virus is potentially at risk of developing FIP. A cat with a weak or malfunctioning immune system is more likely to pick up the disease and develop the full blown FIP syndrome. In practice, we only really see the disease in cats less than two years of age and more than 80% will show the symptoms within their first year. The virus is shed in the saliva and stool. Almost all cases of transmission are from an infected (carrier) mother to her kittens. If it's going to develop the full blown syndrome of FIP, it has probably already contracted the virus from its mother. We also see the disease more commonly in multiple cat households.

Symptoms of FIP
Cats that have been initially exposed to the feline corona virus usually show no obvious symptoms. Some cats may show mild upper respiratory symptoms such as sneezing and runny eyes. Other cats may experience a few days of diarrhoea. Only a small percentage of cats that are exposed to the feline corona virus develop FIP, and this usually shows itself within a month or two, or as long as two years.

There are two major forms of FIP, 'wet' and 'dry' form. Generally, cats will exhibit the signs of the 'dry' form FIP more slowly than the 'wet' form. Symptoms generally include chronic weight loss, depression, anaemia, and a persistent fever that does not respond to antibiotic therapy and a yellow colour to the skin and mucous membranes.

The 'wet' form of FIP is more common and characterized by an accumulation of fluid in the abdomen and in the chest. Early in the disease, the cat may exhibit similar symptoms to the dry form, including weight loss, anorexia, and depression. The wet form of the disease often progresses rapidly, and the cat may develop a swollen belly due to fluid accumulation in the abdomen. When the fluid accumulation becomes excessive, it may become difficult for the cat to breathe normally.

FIP can be difficult to diagnose because each cat can display different symptoms that are similar to those of many other diseases, especially liver disease. We will use a combination of symptoms, age, and a general blood test to help us diagnose FIP. There is a corona virus test, but this is not very accurate, because many cats may have antibodies to corona virus and not develop the FIP syndrome. We will still use this test as a negative test will rule out FIP.

Treatment and Prognosis:
Unfortunately, there is no known cure or effective treatment for FIP at this time. Some treatments may induce short-term remissions in a small percentage of cats; however, FIP is a fatal disease. Treatment is generally aimed at supportive care, such as good nursing care and nutrition, and alleviating the inflammatory response of the disease. Cats with FIP are often treated with corticosteroids and antibiotics. Supportive care may also include fluid therapy and draining accumulated fluids. You must understand that this is a fatal disease and we will recommend euthanasia when your cats quality of life is deteriorating.

There is a vaccine that has been produced for FIP. We do not use this vaccine at our clinic as it is not effective in preventing the disease in the cats most at risk.