Can FIP in Cats Be Cured? What the Evidence Shows

Feline Infectious Peritonitis (FIP) was once considered almost always fatal, but that reality has changed. Today, antiviral treatment built on GS-441524 sends the large majority of treated cats into lasting remission, and a monotherapy protocol reported a 92% success rate at UC Davis (Pedersen, 2019). No responsible provider can promise a cure, but FIP is now a treatable disease when caught and managed under veterinary supervision.

A cat resting comfortably at home.

Can FIP in cats be cured?

FIP is now a treatable disease, and most cats who complete a full antiviral protocol reach lasting remission rather than dying from the illness. The clinical goal is remission, meaning the virus is suppressed, symptoms resolve, and the cat returns to normal life. We are clear about what the data shows and what it does not: the word used in veterinary medicine is remission, not a blanket promise.

The change came from GS-441524, the antiviral at the core of modern FIP treatment. Since 2019, more than 100,000 cats have been treated across the CureFIP network, a scale that simply did not exist when FIP was treated as a death sentence.

Remission is realistic, but it depends on early diagnosis, the correct dose for the form of FIP, and completing the full course. Stopping early is one of the most common reasons a case relapses.

What is FIP and what causes it?

FIP is a serious disease caused by a mutation of feline coronavirus (FCoV), a common and usually harmless gut virus in cats. In a minority of cats, that virus mutates and triggers an aggressive, body-wide inflammatory response that becomes FIP.

FIP is not spread cat to cat as FIP itself. The underlying feline coronavirus is contagious, but the mutation that causes FIP happens inside an individual cat. This is one of several feline infections that can progress quietly, which is why FIP appears on lists of feline viruses vets often diagnose too late.

Young cats, cats in multi-cat households, and recently rehomed kittens carry higher risk. If your veterinarian raises the possibility of FIP, our guide on what to do if your vet suspects FIP walks through the first steps.

What are the four forms of FIP?

FIP takes four forms, wet, dry, ocular, and neurological, and each one shapes the treatment plan and the dose. Recognizing which form your cat has is the first step toward the right protocol.

Wet (Effusive) FIP

Wet FIP is marked by fluid buildup in the abdomen or chest, which can cause a swollen belly or labored breathing. It tends to progress quickly, so prompt diagnosis matters. Jaundice, or yellowing of the gums and eyes, can also appear, and our guide to jaundice in cats explains why.

Dry (Non-effusive) FIP

Dry FIP develops without significant fluid buildup and is often harder to spot. Signs can include weight loss, persistent fever, poor appetite, and inflammatory masses in the organs. Because it is subtle, dry FIP is sometimes diagnosed later than wet FIP.

Ocular FIP

Ocular FIP affects the eyes and may cause color changes in the iris, cloudiness, inflammation, or vision problems. It requires a higher antiviral dose because the eye is a protected site the virus can hide in.

Neurological FIP

Neurological FIP involves the brain and spinal cord and can cause wobbliness, seizures, behavioral changes, or loss of coordination. Like ocular FIP, it needs a higher dose to reach the central nervous system across the blood-brain barrier.

What is GS-441524 and why is it the core of FIP treatment?

GS-441524 is the antiviral nucleoside analog at the heart of modern FIP treatment, and it works by blocking the virus from replicating inside the cat's cells. It is the hero ingredient of CureFIP and the molecule that turned FIP from a fatal diagnosis into a treatable one.

The landmark evidence comes from UC Davis, where GS-441524 monotherapy reported a 92% success rate (Pedersen, 2019). That study forms the backbone of how injectable protocols are dosed and scheduled today. For a deeper look, see our breakdown of how effective GS-441524 treatment is for FIP.

GS-441524 is delivered in two main routes: daily subcutaneous injectables and oral capsules. The route and strength are chosen with your veterinarian based on the cat's weight, the form of FIP, and how well the cat tolerates handling.

What are the GS-441524 injectable options and doses?

CureFIP offers GS-441524 injectables in several concentrations so the volume can be matched to your cat's weight. Every injectable follows the same daily schedule and the same 84-day protocol. Dose figures below are matched to the four forms of FIP and come directly from the product catalog.

Form of FIP	Dose	Schedule	Duration
Wet	6 mg/kg	1 subcutaneous injection per day	84 days
Dry	8 mg/kg	1 subcutaneous injection per day	84 days
Ocular	10 mg/kg	1 subcutaneous injection per day	84 days
Neurological	10 mg/kg	1 subcutaneous injection per day	84 days

Reference for injectable dosing and duration: Pedersen et al., UC Davis (PMC6435921).

The available injectable products and prices are:

• GS-441524 Antiviral Injectables | 15mg/ml, 8ml | $49.00

• GS-441524 Antiviral Injectables | 20mg/ml | $69.00 (8ml, 10ml)

• GS-441524 Antiviral Injectables | 30mg/ml | $89.00 (8ml, 10ml)

• GS-441524 Antiviral Injectables, 40mg/ml | $119.00 (8ml, 10ml)

• GS-441524 Antiviral with Vitamin B12 | 20mg/ml | $75.00 (8ml, 10ml)

• GS-441524 Antiviral with Vitamin B12 | 30mg/ml | $95.00 (8ml, 10ml)

The higher-concentration options mean a smaller injection volume for larger cats. Your veterinarian will confirm the exact strength and daily dose based on your cat's current weight.

Is there an oral option for FIP treatment?

Yes, CureFIP offers an oral dual-antiviral option that pairs GS-441524 with EIDD-1931 in a single capsule, dosed by weight rather than by injection. This route is positioned for wet and dry FIP and is given once daily for a recommended 12 weeks.

Weight band	GS-441524	EIDD-1931
<5.5 lb	25 mg	5 mg
5.5-11 lb	35 mg	8 mg
>11 lb	50 mg	12 mg

The product is Cure FIP™ Oral Capsules | $129.00, taken as 1 capsule per day. Some regions note it is not recommended once ocular or neurological signs are present, or if the cat cannot eat or defecate, so your veterinarian should confirm it fits your cat's case.

The dual-antiviral approach has its own body of evidence. In a study of previously relapsed cats, the dual antiviral protocol achieved 78.3% remission (Li and Cheah, 2025). You can read more in our overview of dual antiviral FIP treatment for American cat owners and why dual antiviral capsules make treatment stronger.

How long does FIP treatment take?

A standard FIP treatment course runs 84 days, which is 12 weeks, given every single day without skipped doses. The daily consistency is as important as the dose itself, because gaps let the virus rebound.

After the 84-day protocol, most cats enter an observation period of about 12 weeks where treatment has stopped but the cat is monitored for any return of symptoms. A cat is generally considered in sustained remission when it stays healthy through observation with normal blood work.

Throughout treatment, your veterinarian tracks progress through weight gain, appetite, activity, and lab values. Our guide to reading your cat's blood work during FIP treatment explains what those numbers mean.

What affects whether a cat reaches remission?

Several factors influence the outcome of FIP treatment, and most of them are within your control when you work closely with your veterinarian. The evidence points to a consistent set of variables.

1. Early diagnosis. The sooner treatment starts, the better the odds, especially before neurological signs appear.

2. Correct dose for the form. Wet, dry, ocular, and neurological FIP each require the right mg/kg, and underdosing risks relapse.

3. Completing the full 84 days. Stopping early because a cat looks better is a leading cause of relapse.

4. Consistent daily dosing. Missed doses give the virus room to rebuild.

5. Monitoring and adjustment. Weight changes and lab results guide dose adjustments over time.

Drug resistance is also worth understanding, because the number on a label is not always the amount that reaches the cat. Our article on what the label number really means covers this in detail.

FAQ

Can FIP be completely cured in cats?

Veterinary medicine uses the term remission rather than cure, and most cats who complete a full antiviral protocol reach lasting remission. GS-441524 monotherapy reported a 92% success rate at UC Davis (Pedersen, 2019), and dual antiviral treatment reported 78.3% remission in previously relapsed cats (Li and Cheah, 2025). Your veterinarian confirms remission after treatment and an observation period.

How long does FIP treatment take?

The standard protocol is 84 days, or 12 weeks, of daily GS-441524 treatment under veterinary supervision. Most cats then enter roughly a 12-week observation period to confirm the FIP has not returned before remission is declared.

Which is better, injections or oral capsules for FIP?

Both deliver GS-441524, and the best choice depends on your cat's form of FIP, weight, and temperament. Injectables follow the UC Davis dosing by form (wet 6 mg/kg, dry 8 mg/kg, ocular and neurological 10 mg/kg), while Cure FIP™ Oral Capsules pair GS-441524 with EIDD-1931 and are positioned for wet and dry cases. Your veterinarian will recommend the right route.

Can neurological or ocular FIP be treated?

Yes, ocular and neurological FIP are treatable, but they require a higher dose of 10 mg/kg to reach the eyes and central nervous system. These forms benefit most from early diagnosis, so contact your veterinarian promptly if you notice eye changes, wobbliness, or seizures.

What happens if I stop FIP treatment early?

Stopping before the full 84 days is a leading cause of relapse, even when a cat looks fully recovered. The virus can rebound and may become harder to treat, so always complete the protocol and let your veterinarian decide when treatment ends.

If your cat has just been diagnosed, you do not have to navigate this alone. Explore the full range of GS-441524 treatment options and talk with our team or your own veterinarian about the plan that fits your cat by visiting CureFIP USA. Every treatment decision should be made together with your veterinarian.