Cat Diseases - Feline Infectious Peritonitis (FIP)

General FIP diagnostic algorithm
  • Feline infectious peritonitis (FIP) is a viral disease that occurs worldwide in wild and domestic cats.
  • It is caused by a type of virus called a coronavirus, which tends to attack the cells of the intestinal wall.
  • This disease exploits weakened and immature immune systems, spreading by way of the white blood cells as they move throughout the body.
  • It is assumed that there are some types of coronaviruses that mutate into the feline infectious peritonitis, either on their own or as the result of a defect in the cat's immune response. Also complicating the matter is that a coronavirus can lie dormant in a cat's body over months before mutating into FIP. The FIP virus then infects the white blood cells, using them as transportation to invade the entire body.
  • FIP is most often seen in young cats, less than 3 years old, but it can be seen at any age. Older cats with weakened immune systems are more likely to acquire this disease.
  • The coronavirus is spread through direct contact via the nose and mouth with infected feces, so sharing litter boxes is a major route of transmission of coronavirus.
  • This disease is comparatively high in multi-cat households as compared to those with a single cat.
    Signs and Symptoms:
  • There are two main categories of FIP: the wet form and the dry form, which have different characteristics.
  • Wet (effusive form) targets the body cavities and progress more rapidly than the dry form.
  • Dry (noneffusive form) targets the various organs.
    • Wet Form
    • fever (long term, unresponsive to treatment)
    • accumulation of fluid in the abdominal cavity
    • accumulation of fluid in the chest cavity
    • distention of abdomen due to fluid build up
    • Diarrhea
    • difficulty breathing due to lung involvement
    • Sneezing, runny nose
    • loss of appetite
    • weight loss
    • depression
    • Dry Form
    • fever (long term, unresponsive to treatment)
    • loss of appetite
    • depression
    • weight loss
    • variable other signs related to organ failure, depending on which organs are involved (commonly involves kidneys, liver, pancreas, nervous system, eyes)
    • Poor growth in kittens
    • Anemia
    • Jaundice
    • Diarrhea
    • Inflammation of various parts of eye
    • Neurological symptoms (e.g., loss of ability to coordinate movements, loss of vision)
feline infectious peritonitis
  • Preventing exposure to coronavirus is the best way to prevent FIP.
  • Keeping cats indoors offers protection, as well as only bringing coronavirus-negative cats into the household.
  • Litter boxes should be kept clean and located away from food and water dishes. The litter should be cleaned of feces daily and totally removed at least once weekly when the box is thoroughly cleaned and disinfected.
  • There is a vaccine available, although its use is controversial. The vaccine is given in the nose, and is designed to produce just a local response to prevent the virus from gaining access to the body. The vaccine is not 100 percent effective, and must be given before natural exposure to coronavirus to be effective.
  • FIP is fatal in more than 95 percent of cases. Fortunately, the disease is very uncommon.
  • This disease is difficult to treat and requires good supportive care.
  • With the non-effusive form, treatment may be given using antibiotics, anti-inflammatories, and immunosuppressive drugs to slow the progress of the disease spread. This is not a cure, but a way to make your cat more comfortable and to prolong its life by a few months.
  • Your veterinarian might decide to remove accumulated fluid from the cavities to reduce pressure as well.
  • If your cat has the effusive form of FIP, there is usually no way of treating the symptoms in any meaningful way, as the disease spreads too rapidly.
  • The overall prognosis for affected cats is poor. There is no specific treatment which seems effective and most patient die due to complications.