FIP in Cats: The 2026 Definitive Guide for India

Feline Infectious Peritonitis (FIP) is a viral disease that was once considered almost always fatal, but that is no longer the story. Today, antiviral medicines built around GS-441524 have changed the outlook completely, and since 2019 more than 100,000 cats have been treated. If your cat has just been diagnosed, take a breath. You are not the first Pawrent to face this, and your cat's odds are better than they have ever been.

This guide is written for Indian caregivers who want clear answers, honest numbers, and a treatment path they can trust and afford. We will walk through what FIP is, how it is diagnosed, and how modern treatment works, always alongside your veterinarian.

A cat resting comfortably at home.

What is FIP in cats?

FIP is a serious viral disease caused by a mutated form of a common feline coronavirus. Most cats carry the harmless intestinal coronavirus with no problem, but in a small number the virus mutates and triggers FIP, which affects the abdomen, chest, eyes, or nervous system.

FIP is not the same as the everyday tummy coronavirus that many cats shed. The mutation is what makes it dangerous. It is most common in young cats under two years and in multi-cat homes, shelters, and catteries.

The good news is simple. FIP now has a clear treatment path, and many families in India have watched their cats reach remission and return to normal life.

What are the four forms of FIP?

FIP has four forms: wet (effusive), dry (non-effusive), neurological, and ocular. Neurological and ocular FIP are two separate forms, not the same thing, and recognising which form your cat has guides the whole treatment plan.

Each form shows up differently, so watching your cat closely helps your veterinarian reach a faster diagnosis.

Form	Main signs	Notes
Wet (effusive)	Fluid buildup in the belly or chest, swollen abdomen, trouble breathing	Often progresses quickly
Dry (non-effusive)	Weight loss, fever, lethargy, poor appetite, no obvious fluid	Harder to spot early
Neurological	Wobbly walking, seizures, behaviour changes, head tilt	Needs medicine that reaches the brain
Ocular	Cloudy eyes, colour changes in the iris, vision problems	Affects the eyes directly

A cat can also shift between forms, and some show a mix of signs. That is why regular check-ins with your veterinarian matter so much.

What are the symptoms of FIP?

The most common early signs of FIP are a fever that does not respond to antibiotics, low energy, poor appetite, and steady weight loss. As the disease progresses, you may see a swollen belly, laboured breathing, yellowing of the gums or eyes, or neurological changes like wobbliness.

Here are signs that should prompt a vet visit:

• A fever that comes and goes and does not respond to antibiotics

• A belly that looks swollen or feels full of fluid

• Rapid weight loss or a shrinking, unkempt appearance

• Cloudy eyes or a change in eye colour

• Wobbly walking, tremors, or seizures

• Ongoing lethargy and loss of appetite

None of these signs alone confirms FIP. They simply tell you it is time to see your veterinarian for proper testing.

How is FIP diagnosed in cats?

FIP is diagnosed by combining your cat's symptoms with blood tests, fluid analysis, and sometimes imaging, because no single test confirms it on its own. Your veterinarian will look at the full picture rather than one number.

Common steps include:

1. A full physical exam and history of symptoms.

2. Blood work, often showing anaemia, high globulin, and a low albumin to globulin ratio.

3. Analysis of any fluid from the belly or chest, which in wet FIP is often thick and yellow.

4. Imaging such as ultrasound to check for fluid or organ changes.

5. In some cases, further lab tests to support the diagnosis.

During treatment, repeat blood work becomes your map. To understand what those numbers mean over the weeks, this guide on FIP blood test results during treatment walks Indian cat parents through it step by step.

How is FIP treated in India in 2026?

FIP is treated with a course of antiviral medicine, most often built around GS-441524, given daily over a standard 84-day (12-week) protocol. This is the same active ingredient behind the UC Davis clinical trial that reported a 92% success rate for GS-441524, and it is the foundation of BasmiFIP treatment.

Treatment is a journey with clear stages, and your cat's form of FIP decides where it starts. There are now both injectable and oral options, which gives families more flexibility than ever.

The BasmiFIP FIP line includes:

• GS-441524 injectable (Basmi FIP Antiviral): 40 mg/ml, 99.4% purity, in an 8 ml vial. This is the primary FIP antiviral, given as a daily injection for the full protocol.

• EIDD-1931 oral capsules: 15 mg per capsule, for wet (effusive) and dry (non-effusive) FIP only.

• Dual Antiviral oral capsules (GS-441524 + EIDD-1931): one capsule per day, used once a cat is stable.

Many Indian clinics have refined their approach in recent years, and you can read real-world lessons from Indian veterinary clinics treating FIP to see how vets are guiding families through it.

GS-441524 injectable dosing by form

The injectable dose depends on which form of FIP your cat has. Your veterinarian will confirm the exact amount for your cat's weight.

FIP form	GS-441524 injectable dose
Wet (effusive)	6 mg/kg daily
Dry (non-effusive)	8 mg/kg daily
Ocular	10 mg/kg daily
Neurological	10 mg/kg daily

Injections are given once daily, 7 days a week, across the 84-day protocol. Ocular and neurological FIP need the higher dose because the medicine must reach the eyes and the brain.

When is EIDD-1931 used, and when is it not?

EIDD-1931 oral capsules are indicated for wet and dry FIP only. They are not recommended for ocular or neurological FIP, or for cats that are not eating or defecating normally.

EIDD-1931 is a potent antiviral, roughly 7.3 times more potent than GS-441524 by weight. Because of this potency, dosing follows clear weight bands.

Cat weight	EIDD-1931 capsules (15 mg)
Under 2.5 kg	1 capsule every 12 hours
2.5 to 5 kg	2 capsules every 12 hours
Over 5 kg	3 capsules every 12 hours

One important safety note. EIDD-1931 is potentially teratogenic, so it must never be given to pregnant, nursing, or breeding cats. Always confirm your cat's status with your veterinarian first.

How do the treatment routes compare?

The right route depends on the FIP form, your cat's stability, and what fits your family. Here is a simple comparison to discuss with your vet.

Route	Best for	Notes
GS-441524 injection	All forms, including ocular and neurological	Daily injection, the standard starting point for severe cases
EIDD-1931 capsules	Wet and dry FIP only	Not for ocular, neurological, or cats not eating and pooping normally
Dual Antiviral capsules	Stable cats after about 30 days of injections	One capsule daily, not during ocular or neurological signs

A common regimen for ocular or neurological FIP is to start with GS-441524 injections for about 30 days, then move to the GS-441524 dual antiviral capsule once the cat is stable. For wet or dry FIP without ocular or neuro signs, some families may start with EIDD-1931 and adjust with their vet over time.

The dual antiviral approach has strong field data behind it. A BasmiFIP field study by Li and Cheah (2025) reported 78.3% remission with dual antiviral therapy in 46 cats, including drug-resistant cases.

What does FIP treatment cost, and is it affordable?

FIP treatment cost in India depends on your cat's weight, the FIP form, and the route your veterinarian chooses, because the dose scales with body weight. There is no single flat number, so the honest answer is that your vet and the treatment team can give you a tailored estimate.

We know cost weighs heavily on many Pawrents. The community has grown precisely because families support each other through the financial side as well as the medical side. For a practical overview of getting started, this clear guide to FIP treatment in India is a helpful next read.

What should you avoid during FIP treatment?

During FIP treatment, avoid certain medicines that can interfere with antiviral therapy. These include fluoroquinolone antibiotics, spot-on flea treatments, lysine, and immune boosters.

Always tell your veterinarian about every product your cat is taking, including supplements. Some organ support products can help alongside treatment, but they are not antivirals.

For example, RX Sciences LiverRx and KidneyRx are supportive nutraceuticals that provide adjunct organ support during a vet-guided treatment plan. They do not treat FIP and should never replace antiviral therapy. They simply support the liver and kidneys while the antiviral does its work.

What happens after the 84-day protocol?

After the 84-day protocol, most cats enter an observation period of about 12 weeks, during which your veterinarian watches for any return of symptoms. If your cat stays healthy and blood work stays stable through this window, your cat is considered to be in remission.

Remission is the goal, and many families reach it. The recovery journey does not end the day the last dose is given, so keep up with follow-up blood work and vet visits.

FAQ

Can FIP in cats be treated successfully?

Yes. FIP is now treatable with antiviral therapy, and since 2019 more than 100,000 cats have been treated. The UC Davis clinical trial reported a 92% success rate for GS-441524, though every cat is different and your veterinarian will guide the plan.

How long does FIP treatment take?

The standard FIP protocol is 84 days, which is 12 weeks of daily antiviral medicine. Most cats then have an observation period of about 12 weeks before they are considered to be in remission.

Is FIP contagious to other cats or to humans?

The mutated virus that causes FIP is not considered easily transmissible from cat to cat, and FIP does not infect humans. The underlying feline coronavirus can spread between cats through litter and shared spaces, so good hygiene helps, and your veterinarian can advise on your specific home.

Can I give EIDD-1931 capsules to a pregnant cat with FIP?

No. EIDD-1931 is potentially teratogenic and must never be given to pregnant, nursing, or breeding cats. Speak with your veterinarian about a safe alternative for these cats.

What is the difference between wet and dry FIP?

Wet (effusive) FIP causes fluid to build up in the belly or chest and often progresses quickly, while dry (non-effusive) FIP causes weight loss, fever, and lethargy without obvious fluid. Both are treatable, though the dry form can be harder to spot early.

You do not have to face this alone, and there is a clear path forward that starts with the right diagnosis. To learn more about the available options and to speak with the team or your own veterinarian, visit the BasmiFIP India team and take that next step for your cat's recovery journey.