Feline Infectious Peritonitis (FIP) is a rare, often misunderstood, viral disease that only affects cats. Because FIP is viral and contagious, it’s more common in multi-cat households and shelters, where multiple cats live together in one space.
While there are still few treatments available for FIP and the prognosis is often fatal, there have been promising studies and advancements in treatment recently. There are also many ways to care for your FIP-positive cat to make the remainder of their lives as comfortable as possible.
What Causes FIP in Cats?
FIP is caused by a feline coronavirus. Feline coronavirus (FCoV) is common in cats, especially in places where multiple cats live together.
FCoV develops in a cat’s digestive tract and is shed through their feces. It spreads when another cat comes into contact with the feces or body fluid that’s infected.
For most cats who contract FCoV, they display mild symptoms like diarrhea or upper respiratory symptoms—or they may never display symptoms at all. Their bodies will process the virus through their feces, and the cat will never develop FIP.
In rare cases, however, the FCoV multiplies and mutates into another strain of feline coronavirus, leading to the development of FIP. This is most often seen in cats younger than 2, but it can happen to cats of any age.
Common Symptoms of FIP in Cats
FIP symptoms will vary from cat to cat and will also depend on what type of FIP the cat has, “dry” or “wet” form. For most cats, no matter the form, early signs of FIP include fever, loss of appetite, and lethargy, and their symptoms can be a combination of dry and wet FIP.
Dry or Non-Effusive FIP
This form of FIP is known as the “dry” form because little to no fluid accumulates in your cat. Instead, inflammatory lesions develop around the blood vessels of some of your cat’s organs, typically their eyes, kidneys, liver, or nervous system.
Because the development of these lesions can differ from cat to cat, the symptoms that present themselves will depend on which organs are affected.
Symptoms of dry form FIP may include:
- Seizure, sudden blindness, and other neurological symptoms
- Bleeding in the eyes
- Excessive thirst and urination
- Weight loss
Wet or Effusive FIP
Wet FIP causes fluid to build up in the cat’s abdomen, known as abdominal distension, or in the chest cavity.
The accumulation of fluid can cause breathing difficulties, as well as damage and inflammation to surrounding blood vessels.
Symptoms of wet form FIP may include:
- A pot-bellied appearance
- Panting or open-mouthed breathing
- Weight loss
- Decreased energy
This type of FIP is most commonly seen in kittens.
Diagnosing FIP in Cats
Because FIP develops as a mutation of the feline coronavirus, it can be difficult to diagnose. Vets may run blood tests, but it’s challenging to distinguish between FCoV that causes no symptoms and FCoV that develops into FIP.
There are also no symptoms that are unique to FIP, so your vet must rule out another potential diagnosis before they can diagnose your cat with FIP.
Most vets will rely on your cat’s history, clinical symptoms, and a combination of medical tests and physical examinations. Your vet may recommend an ultrasound or an X-ray, as well as take a sample (if wet FIP is suspected) of the fluid accumulating in your cat’s abdomen.
Using all of these pieces, your vet may diagnose your cat with FIP if:
- Blood work shows a low number or an unusually high number of white blood cells
- Elevated concentrations of protein in your cat’s blood
- Signs of yellowing in their gums or eyes
In many cases, your vet may also recommend a biopsy after FIP is suspected to further help confirm the diagnosis.
How to Care for Your Cat with Feline Infectious Peritonitis
If your cat has been diagnosed with FIP, it’s important that you help your cat feel as comfortable and happy as possible at home. Here are a few ways to help care for your FIP-diagnosed cat.
Encourage Your Cat to Eat
FIP can suppress your cat’s appetite, and many cats will lose a lot of weight during their diagnosis. It’s important to encourage your cat to eat as much as possible to increase their energy levels and support their body functions.
You can encourage your cat to eat by using their favorite snacks or trying especially smelly, canned food that will be hard for your kitty to resist.
Keep Your Cat Comfortable
Especially with wet FIP, your cat may have difficulty breathing and struggle to climb or jump on furniture. Adding pet beds around your home can give your cat comfortable spots to lay in.
You can also try adding stairs near your couch or bed, so your cat can easily cuddle with you without having to climb or jump onto the furniture.
Minimize Stress for Your FIP-Positive Cat
While there is still little known about the factors that lead to FIP, stress can take a toll on your cat’s immune system.
Provide your cat with a quiet environment away from the hustle and bustle of your home. Giving your cat hiding spots like cubby holes or covered beds can also help reduce their stress.
Treatment Options for FIP
FIP was seen as an untreatable disease, but there have been recent advancements in antiviral medications that have shown promising results. While they have yet to be approved by the FDA, these medications may provide new options for pet parents in the future.
Right now, the most common treatments are supportive care options, like fluid drainage, blood transfusions, and pain medication to make your cat more comfortable.
Sometimes steroids or immunosuppressive medications can be used to decrease virus-antibody complexes in the blood vessels.
Do You Think Your Cat May Have FIP?
If your cat is showing any signs of FIP, it’s important to contact a veterinarian right away.
While an in-person vet can perform blood tests and the necessary physical exams to make a complete diagnosis, a virtual appointment with one of our qualified vets can answer your questions and advise on the next steps that are right for your cat’s unique situation.
Book an appointment today to get expert advice from a licensed veterinarian on your schedule.