FIP in Cats: Complete Guide for Filipino Caregivers
Key takeaway: Feline Infectious Peritonitis (FIP) is a serious viral disease in cats, but it is no longer a hopeless one. With GS-441524 antiviral treatment, UC Davis reported a 92% success rate, and since 2019 more than 100,000 cats have been treated worldwide. If you catch the signs early, work with your veterinarian, and follow the full protocol, your cat's odds are better than they have ever been.
If you are a Filipino Pawrent who just heard the letters "FIP" from your vet, take a breath. You are not the first to face this, and you are not alone. This guide walks you through what Feline Infectious Peritonitis (FIP) is, how to spot it, how it is diagnosed, and how BasmiFIP treatment works, step by step.
A cat resting comfortably at home.
What Is Feline Infectious Peritonitis (FIP) in Cats?
Feline Infectious Peritonitis (FIP) is a disease caused when a common, usually harmless feline coronavirus mutates inside a cat's body and triggers a severe immune reaction. It is not the same virus as human COVID, and you cannot catch FIP from your cat.
The coronavirus that leads to FIP is very common in multi-cat homes, shelters, and catteries. In most cats it causes nothing worse than mild tummy upset. In a smaller number of cats, usually young ones under two years old, the virus changes form and spreads through the body.
FIP was once considered almost always fatal. That changed with GS-441524, the antiviral that sits at the heart of modern treatment. Today, FIP is a disease many families treat and overcome, and for a deeper background you can read this complete FIP guide for Filipino cat parents.
What Are the Symptoms of Feline Infectious Peritonitis (FIP)?
The most common early signs of Feline Infectious Peritonitis (FIP) are a fever that does not respond to antibiotics, loss of appetite, weight loss, and low energy. Many Pawrents notice their once-playful kitten has become quiet and withdrawn.
As FIP progresses, the symptoms depend on which form the disease takes. Watch closely for:
A swollen, fluid-filled belly (a classic sign of the wet form)
Labored or fast breathing if fluid builds up around the lungs
Yellowing of the gums, eyes, or skin (jaundice)
Eye changes such as cloudiness, color changes, or inflammation
Wobbliness, loss of balance, tremors, or seizures
Stunted growth in kittens
A fever that keeps coming back despite antibiotics is one of the biggest red flags. Antibiotics do not treat a virus, so if your cat is not improving, ask your veterinarian about FIP.
What Are the Four Forms of Feline Infectious Peritonitis (FIP)?
Feline Infectious Peritonitis (FIP) has four forms: wet (effusive), dry (non-effusive), ocular, and neurological. Each form affects the body differently and guides how treatment is chosen.
Form of FIP | Main sign | Key note |
Wet (effusive) | Fluid in the belly or chest | Often progresses quickly |
Dry (non-effusive) | Organ inflammation, vague illness | Harder to diagnose |
Ocular | Eye inflammation or color change | A separate form; needs higher dosing |
Neurological | Wobbliness, tremors, seizures | A separate form; needs higher dosing |
It is important to know that ocular FIP and neurological FIP are two distinct forms, not one combined type. They matter because they require a higher antiviral dose to reach the eyes and the brain. Eye changes do not always mean FIP, since other viruses can inflame the eyes too, so it helps to understand conditions like corneal ulcers linked to feline herpesvirus when you talk with your vet.
How Is Feline Infectious Peritonitis (FIP) Diagnosed?
Feline Infectious Peritonitis (FIP) is diagnosed through a combination of clinical signs, blood tests, and sometimes fluid analysis, because no single test confirms it on its own. Your veterinarian builds the picture from several clues together.
Common diagnostic steps include:
A physical exam and full history, including your cat's age and living situation.
Blood work that often shows high globulin, a low albumin-to-globulin ratio, anemia, and high bilirubin.
Analysis of any belly or chest fluid, which in wet FIP is typically yellow, thick, and protein-rich.
Additional tests such as PCR or imaging when your vet needs more detail.
Diagnosis can feel slow and frustrating, especially with the dry form, which hides behind vague symptoms. Stay patient and keep working with your veterinarian. A clear diagnosis is the foundation of a successful recovery journey.
How Does BasmiFIP Treat Feline Infectious Peritonitis (FIP)?
BasmiFIP treats Feline Infectious Peritonitis (FIP) with GS-441524, the antiviral proven to stop the virus from replicating, delivered over a full 84-day protocol under veterinary guidance. GS-441524 is the hero ingredient behind the 92% success rate that UC Davis reported in its clinical trial.
The BasmiFIP GS-441524 injectable is 40 mg/ml at 99.4% purity in an 8 ml vial. It is given as one injection every day, seven days a week, for 12 weeks. Finishing the full course is essential, even when your cat looks and feels completely well partway through.
GS-441524 Dosing by Form of FIP
The correct dose depends on which form of Feline Infectious Peritonitis (FIP) your cat has, because ocular and neurological forms need a higher dose to reach protected areas of the body.
Form of FIP | GS-441524 dose |
Wet (effusive) | 6 mg/kg daily |
Dry (non-effusive) | 8 mg/kg daily |
Ocular | 10 mg/kg daily |
Neurological | 10 mg/kg daily |
Your veterinarian will weigh your cat regularly and adjust the dose as your cat gains back weight. Never guess the dose on your own.
Oral Options for Feline Infectious Peritonitis (FIP)
BasmiFIP also offers oral options for Feline Infectious Peritonitis (FIP) in suitable cases. EIDD-1931 oral capsules are indicated for wet and dry FIP only, and are not for ocular or neurological FIP, or for cats that are not eating and defecating normally.
There is also a Dual Antiviral oral capsule that combines GS-441524 with EIDD-1931. A field study by Li and Cheah (2025) reported a 78.3% remission rate for the dual-antiviral approach. The dual capsule is generally introduced after about 30 days of injections, or once a cat is stable, and is not used during ocular or neurological symptoms, during vomiting or diarrhea, or in cats under one year with wet FIP.
One safety point that never changes: EIDD-1931 must never be given to pregnant, nursing, or breeding cats. Always let your veterinarian decide which product and route fit your cat.
How Treatment Routes Compare
Treatment route | Best for | Reported figure |
GS-441524 injectable | All four forms, including ocular and neurological | 92% success rate (UC Davis) |
Dual Antiviral capsule | Stable cats after about 30 days, wet or dry only | 78.3% remission (Li and Cheah 2025) |
EIDD-1931 capsule | Wet or dry FIP only, cat eating and pooping normally | Discuss with your vet |
What Should You Avoid During Feline Infectious Peritonitis (FIP) Treatment?
During Feline Infectious Peritonitis (FIP) treatment, certain products can interfere with the antiviral or stress your cat's system, so they are best avoided. Ask your veterinarian before giving anything new.
Avoid these during the treatment period:
Fluoroquinolone antibiotics
Spot-on flea treatments
Lysine supplements
Immune boosters
These can clash with the protocol or muddy the picture when your vet is tracking progress. When in doubt, pause and check first.
How Can You Support Your Cat During Feline Infectious Peritonitis (FIP) Treatment?
You can support your cat during Feline Infectious Peritonitis (FIP) treatment by keeping a calm environment, feeding a nutritious high-protein diet, tracking weight and symptoms daily, and attending every vet recheck. The antiviral does the heavy lifting, but your daily care matters too.
FIP treatment can be hard on the liver and kidneys, so your vet may suggest adjunct organ support. LiverRx and KidneyRx are supportive nutraceuticals, not antivirals, and they do not treat FIP by themselves. They are meant to sit alongside veterinary-guided antiviral treatment.
LiverRx for cats combines SAMe, Silybin from milk thistle, Vitamin E, and Vitamin C to support liver health. KidneyRx blends ingredients like Omega-3, L-Carnitine, and cranberry extract to support kidney function. Think of them as gentle backup, never a replacement for the antiviral.
Keep a simple daily log of temperature, appetite, weight, and energy. These notes help your veterinarian fine-tune the plan and catch any problem early. Treatment is a journey, and we will walk you through each stage alongside your vet.
What Happens After the 84-Day Protocol for Feline Infectious Peritonitis (FIP)?
After the 84-day protocol for Feline Infectious Peritonitis (FIP), your cat enters an observation period of about 12 weeks to confirm that remission is holding. During this time there is no antiviral, and your vet watches for any return of symptoms.
If your cat stays healthy and bloodwork looks good through the observation window, your vet will consider your cat in sustained remission. This is the moment so many Filipino families work toward, and it is a real one.
Throughout treatment and observation, stay connected with other Pawrents who have walked this road. Community support in the Philippines is strong, and the shared experience of families who have been through FIP can carry you through the hard days.
FAQ
Can Feline Infectious Peritonitis (FIP) be treated successfully?
Yes, Feline Infectious Peritonitis (FIP) can be treated successfully with GS-441524 antiviral therapy. UC Davis reported a 92% success rate in its clinical trial, and since 2019 more than 100,000 cats have been treated, so your cat's chances are far better than they once were.
Is Feline Infectious Peritonitis (FIP) contagious to humans or other cats?
Feline Infectious Peritonitis (FIP) itself is not contagious to humans, and you cannot catch it from your cat. The underlying feline coronavirus can spread between cats, but only a small number of infected cats ever develop FIP.
How long is treatment for Feline Infectious Peritonitis (FIP)?
Treatment for Feline Infectious Peritonitis (FIP) follows an 84-day protocol, meaning 12 weeks of daily antiviral dosing. After that comes an observation period of about 12 weeks to confirm your cat stays well before declaring sustained remission.
Can I give supplements like LiverRx or KidneyRx instead of the antiviral?
No. LiverRx and KidneyRx are supportive nutraceuticals that help the liver and kidneys, and they do not treat Feline Infectious Peritonitis (FIP) on their own. They are meant to be used alongside veterinary-guided GS-441524 treatment, never as a replacement for it.
Is oral treatment an option for every cat with Feline Infectious Peritonitis (FIP)?
Not for every cat. Oral EIDD-1931 capsules are suitable for wet and dry Feline Infectious Peritonitis (FIP) only, and are not used for ocular or neurological forms, or for cats that are not eating and defecating normally. EIDD-1931 must also never be given to pregnant, nursing, or breeding cats, so let your veterinarian choose the right route.
There is a clear path forward for your cat, and it starts with the right diagnosis and a treatment plan you can trust. To learn more about the options and talk through the next step, visit the BasmiFIP Philippines team and work closely with your own veterinarian. You are not alone on this recovery journey, and many families have walked it before you.
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