Feline Infectious Peritonitis: It Could Be Fatal for Your Cat

This is a really tough disease, because it's hard to diagnose, and there's no cure yet. Read on to learn more about this potentially fatal illness.
Feline Infectious Peritonitis: It Could Be Fatal for Your Cat

Last update: 11 December, 2018

Feline infectious peritonitis (FIP) is a complex, serious illness that could potentially be fatal for your cat. It’s mostly common in cat colonies, shelters, and breeding centers, but all cats are vulnerable to it. This is especially true for cats between 6 months to 2 years old, and cats for older than 10 years.

Feline infectious peritonitis

A worldwide disease, feline infectious peritonitis comes from a mutation of feline coronavirus. It also seems to be more common in purebred cats.

cat veterinarian

Reaching a firm diagnosis of this disease usually isn’t easy. Often, the diagnosis only comes after the cat has already died. There’s also no effective treatment for it if you spot FIP at an early stage. There is a vaccine, but it isn’t 100% effective.

However, don’t panic if your vet tells you your cat has feline coronavirus. It’s extremely common in house cats, and generally just causes a bit of diarrhea

But there seem to be times when the virus mutates and turns into feline infectious peritonitis. That’s why makes coronavirus so dangerous. Still, the mutation only happens with about 1% of cats that contract it.

Hard to diagnose and still without a cure, feline infectious peritonitis seems to show up as a result of a coronavirus mutation. This second condition isn’t nearly as serious, likely just causing diarrhea. 

How cats get coronavirus

A cat infected with coronavirus can spread it to others in the following manners:

  • Feces
  • Urine
  • Sneezing/mucus

Experts think these are also potential risk factors: 

  • Food bowls
  • Cat beds
  • Transmission from a pregnant mother to a fetus

Warning signs that your cat has FIP

Once your cat is infected, it could take two weeks or even years for the first symptoms of this awful disease to appear.

There are three classifications:

  • Wet, or effusive.
  • Dry, or non-effusive.
  • Intermediate (a combination of the other two)

The early symptoms of FIP aren’t very specific to this disease, and they could seem like signs of another illness. For example, there’s:

  • Fever
  • Lack of appetite
  • Weight loss
  • Lethargy
  • Secretions from the nose and eyes

The acute form of FIP

The “wet” kind of FIP is the more serious, acute form of this disease. Along with the aforementioned symptoms, your cat will experience ascites (a build-up of fluid in the peritoneal cavity), weight loss, and anemia. These could show up within very different time frames between one cat and another.

That fluid build-up causes progressive swelling, though it’s not painful. It could also start to have pericardial effusion (fluid build-up around the heart). Nerve and eye symptoms are possible, though rare with wet FIP.

The dry form of feline infectious peritonitis

There’s no ascitic fluid in the dry form, but it could still impact several parts of your cat’s body, such as:

  • Uveal tract.
  • Kidneys.
  • Liver.
  • Central nervous system.

Their fur will also start to look ragged. A lot of cats also show signs of jaundice (yellow eyes, nose, and gums).

Non-effusive FIP can take a few months to progress through all these symptoms, but it always ends in the cat’s death.

Potential causes of the coronavirus mutation

cat in bed

We might not know exactly what causes this virus to mutate, but we know it has a lot to do with a cat’s immune system. We’ve figured that out because it mostly happens to them when they’re either young or old, and many have immunodeficiency issues prior to death.

The mutation could also happen as a result of a poor immune response to feline coronavirus. Of course, you can’t rule out genetic factors or intense stress, either.

Don’t lose hope. Take care of your cat and love them with all your heart. That’s one prescription that helps with any problem.


This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.