A blog by April
My first experience with FIP was over 20 years ago. He was an older cat who had the wet form. All the veterinarian could do was drain the fluid and try to keep him comfortable. It was expensive and didn’t help him. Fast forward to last October. One of Sunny’s kittens that Amber and Jim adopted was always hungry but could only eat small portions and was losing weight. He was only seven months old. After almost $500 at their vet they were told it could be giardia or FIP and if it was FIP the prognosis wasn’t good. They could have opted for additional testing but decided to try to treat it as giardia first. The medication wasn’t helping, and he was so anemic his tongue and gums were white, and he was down to 4 pounds. During this time Flea Treats had a booth at the Long Beach Pet Fair and when Amber and Jim arrived, they were so sad – they thought they were going to lose Mouse. I’ll skip the suspense – Mouse is doing fabulous! We were talking to one of the rescue organizations and mentioned Mouse’s condition. She said there is a new medication, and she’s treated many cats with FIP with great success. Of course we couldn’t have been happier, but why did the vet tell us it wasn’t treatable? All six of the kittens celebrated their 1st birthday March 23, 2025. Then I noticed that Bauhaus wasn’t playing like usual and he was super mellow. He ate fine but seemed off. Then his eyes started looking like they were bothering him, so I began Googling. I discovered there is an ocular form of FIP and figured that was it. I reached out to the ladies at the rescue, sent some photos and they agreed it was ocular FIP. I went to them to get the medicine and within a couple days his eyes were back to normal and he’s playing like crazy again! I made sure it wouldn’t be harmful to give him the medication if it wasn’t FIP. I would have taken him to my vet if there was a test for FIP – there isn’t. They do tons of tests to rule out everything else before diagnosing FIP which could cost quite a bit. Before starting this blog, I called my vet to ask if they treated FIP. They said they would need to do bloodwork, ultrasound, etc. and if they thought he was a good candidate they would prescribe the medication that I would have to get at a pharmacy and said it would cost about $1000. It still seems like vets aren’t comfortable diagnosing and treating FIP – hopefully that will change soon. The medication just became available last year – how lucky we are! We hope none of your cats get FIP but hope this information could be lifesaving if they do. Below is some information about FIP from WebMD.
What is it?
From WebMD: Feline infectious peritonitis (FIP) is a viral disease caused by a feline coronavirus that affects wild and domestic cats. This type of coronavirus is different from the one that causes COVID-19 in people. FIP includes two forms: feline enteric coronavirus (FECV), which is common and usually mild, and feline infectious peritonitis virus (FIPV), which is much more dangerous. Although doctors don’t believe FIP in cats is contagious, it’s a serious disease. When a cat gets FIP, it gets worse and will likely kill them without treatment. Cats under age 2 and older than 13 have a higher chance of getting the disease.
FIP Symptoms
Early signs of FIP in cats can vary but often include a rising and falling fever, loss of appetite, and energy loss. As time goes by, infected cats may have more FIP symptoms that depend on the form of FIP.
FIP has a “dry” and a “wet” form. Infected cats can have symptoms of only one form or a mix of both.
Dry FIP. The dry form of FIP causes infections and inflammation. This can affect your cat’s brain, eyes, liver, kidneys, lungs, and skin. Cats with this form often have seizures and may move in strange or uncoordinated ways. They might also drink and pee a lot, throw up, lose weight, and get jaundice.
Wet FIP. This form of the disease causes fluid to collect in the belly, giving the cat a pot-bellied look. Fluid can also gather in the chest, making it hard for the cat to breathe. Wet FIP harms the blood vessels, leading to inflammation and fluid leaking from the blood into the abdomen and chest.
Once a cat has FIP in either form, the symptoms tend to get worse with time. Without treatment, euthanasia (or putting the cat “to sleep”) is often necessary in a matter of weeks or months.
Diagnosis of FIP
FIP is hard to diagnose. Many of its symptoms could also be symptoms of other health issues in your cat. No single blood test is available to confirm FIP. Although tests can help support a veterinarian’s diagnosis, none of them is 100% accurate.
Feline Infectious Peritonitis Treatment
FIP was long considered an untreatable disease until recently when the FDA approved drugs to help treat it.
GS-441524 for FIP. GS-441524 is a tablet or liquid oral antiviral drug that may cure FIP. The standard treatment lasts 84 days, but research shows a shorter 42-day treatment might work just as well. Ask your veterinarian which is best for your cat.
“We don’t have long-term studies of this [drug] since it has recently become FDA-approved,” Yarde says. “But 84% to 85% of these kitties are surviving at least the first six months, which is a complete turnaround from just a year ago when 95% of these cats were dying.”
Other FIP treatments may include supportive care, such as drainage of built-up fluid and blood transfusions. Talk to your veterinarian to help you decide the best treatment option for your cat. 💕