FIP Remission in Cats: What It Means and How to Know

Remission in Feline Infectious Peritonitis (FIP) means the disease is inactive: your cat's clinical signs have resolved, bloodwork has returned toward normal ranges, and your veterinarian confirms the cat is stable after completing treatment. You know FIP treatment has worked when a cat finishes the full 84-day GS-441524 protocol, stays symptom-free, and holds steady through an additional observation period that your veterinarian oversees. Remission is a clinical judgment your vet makes, not a single day on the calendar.

A cat resting comfortably at home.

What does remission mean in Feline Infectious Peritonitis (FIP)?

Remission in Feline Infectious Peritonitis (FIP) means the virus is suppressed to the point where it no longer causes active disease, and your cat looks and behaves like a healthy cat again. It is the clinical goal of a full GS-441524 course, and it is confirmed by a combination of physical recovery and laboratory results rather than by appearance alone.

Remission is different from feeling better mid-treatment. A cat can perk up within the first week or two, but early improvement is not the same as sustained remission.

GS-441524 is the antiviral at the core of modern FIP treatment. GS-441524 monotherapy carries a 92% success rate reported by UC Davis (Pedersen, 2019), and across our network more than 100,000+ cats have been treated since 2019.

How do you know when FIP treatment has worked?

You know Feline Infectious Peritonitis (FIP) treatment has worked when your cat completes the full 84-day protocol, shows no return of clinical signs, and your veterinarian confirms that bloodwork markers have normalized and stayed stable. Confirmation rests on three pillars: how the cat looks, what the bloodwork shows, and whether that stability holds over time.

The practical milestones most caregivers and vets watch for are:

1. Appetite and weight return. Your cat eats willingly and gains or holds a healthy weight.

2. Energy and behavior normalize. Grooming, play, and normal interaction come back.

3. Fluid resolves. In wet FIP, abdominal or chest effusion clears.

4. Fever settles. Temperature stays in the normal range without relapse.

5. Bloodwork improves. Key markers move back toward normal and stay there.

Each milestone matters, but none of them alone equals remission. Your veterinarian reads them together. If you are still early in the journey, our guide on what to expect during your cat's first week on GS-441524 sets realistic expectations for those first signs of turnaround.

What are the signs of GS-441524 remission?

The signs of GS-441524 remission are steady weight, a strong appetite, normal energy and grooming, resolved fluid or eye and neurological signs, and bloodwork that has returned toward normal and stayed there through the end of treatment. Evidence shows the clearest confirmation comes from tracking these markers over the full protocol rather than a single good week.

Common laboratory markers your veterinarian may monitor include:

• Globulin and the albumin-to-globulin (A:G) ratio moving back toward normal.

• Total white cell picture stabilizing.

• Haematocrit / red cell count recovering from anaemia.

• Bilirubin normalizing where it was elevated.

These are the same markers that were abnormal at diagnosis, which is why baseline testing at the start matters so much. Because FIP can be confused with other conditions, reviewing common FIP misdiagnoses can help you understand why your vet leans on labs, not just symptoms, to judge recovery.

How does remission look across the four forms of Feline Infectious Peritonitis (FIP)?

Feline Infectious Peritonitis (FIP) takes four forms, wet, dry, ocular, and neurological, and each shapes both the dosing and the way remission is confirmed. Below, each form is presented in its own subsection to mirror the four-row GS-441524 dosing structure. For a fuller symptom picture, our complete guide to cat FIP symptoms walks through what each form looks like at diagnosis.

Wet / Effusive Feline Infectious Peritonitis (FIP)

Wet FIP is defined by fluid buildup in the abdomen or chest, and remission here is marked by that effusion clearing and not returning. Because fluid is visible and measurable, wet FIP often shows some of the earliest signs of response.

Under the standard GS-441524 injectable protocol, wet FIP is dosed at 6 mg/kg. Your veterinarian confirms remission when the fluid is gone, breathing and comfort are normal, and bloodwork holds steady.

Dry / Non-effusive Feline Infectious Peritonitis (FIP)

Dry FIP produces internal inflammation without obvious fluid, so remission is confirmed mainly through bloodwork, weight, energy, and resolution of organ-related signs. Because there is no fluid to watch clear, dry FIP relies more heavily on laboratory trends.

Under the standard GS-441524 injectable protocol, dry FIP is dosed at 8 mg/kg. Remission is judged by sustained normal appetite and activity alongside improving markers over the 84-day course.

Ocular Feline Infectious Peritonitis (FIP)

Ocular FIP affects the eyes, causing color changes, cloudiness, or vision problems, and remission is marked by these eye signs resolving and staying resolved. Your veterinarian will examine the eyes directly as part of confirmation.

Under the standard GS-441524 injectable protocol, ocular FIP is dosed at 10 mg/kg. Because eye involvement can signal deeper spread, dosing is set higher than for wet or dry forms.

Neurological Feline Infectious Peritonitis (FIP)

Neurological FIP affects the brain and spinal cord, producing signs such as wobbliness, seizures, or behavior changes, and remission is confirmed when these signs resolve and do not recur. Neurological cases need the drug to cross into the central nervous system, which is why they are watched especially closely.

Under the standard GS-441524 injectable protocol, neurological FIP is dosed at 10 mg/kg. Your veterinarian will assess coordination, reflexes, and behavior over time to confirm stability.

GS-441524 dosing by FIP form

FIP form	GS-441524 injectable dose	Schedule	Duration
Wet / Effusive	6 mg/kg	1 subcutaneous injection per day	84 days (12 weeks)
Dry / Non-effusive	8 mg/kg	1 subcutaneous injection per day	84 days (12 weeks)
Ocular	10 mg/kg	1 subcutaneous injection per day	84 days (12 weeks)
Neurological	10 mg/kg	1 subcutaneous injection per day	84 days (12 weeks)

Doses above are drawn from the GS-441524 Antiviral Injectable catalog (reference: Pedersen et al., UC Davis, PMC6435921). Your veterinarian sets the exact dose for your cat and adjusts as weight changes.

What is the 84-day protocol and why does it matter for remission?

The 84-day protocol is the standard 12-week course of daily GS-441524 that underpins remission in Feline Infectious Peritonitis (FIP). Completing all 84 days matters because stopping early, even when a cat looks well, is one of the most common reasons the disease returns.

CureFIP offers GS-441524 in two injectable strengths: the GS-441524 Antiviral Injectable at 20 mg/ml, 8ml for AU$79.00, and the GS-441524 Antiviral Injectables at 30 mg/ml, 8ml for AU$99.00. Both are available With B12 or Without B12 and are given as 1 subcutaneous injection per day, 7 days a week.

There is also the CureFIP Oral Capsules - Dual-Action Formula at AU$139.00, a GS-441524 and EIDD-1931 combination positioned for wet and dry FIP. Dual antiviral therapy has a reported 78.3% remission rate (Li and Cheah, 2025), and some regions note the oral dual route is not recommended once ocular or neurological signs are present or the cat cannot eat or defecate. You can read more in our overview of dual antiviral therapy for FIP in Australia.

How does your veterinarian confirm FIP remission?

Your veterinarian confirms Feline Infectious Peritonitis (FIP) remission by comparing end-of-treatment bloodwork against the baseline taken at diagnosis, checking that clinical signs have resolved, and then observing your cat through a monitoring period after the last dose. Remission is a clinical decision your vet makes with the full picture in front of them.

A typical confirmation sequence looks like this:

1. Repeat bloodwork near the end of the 84-day protocol to check that markers have normalized.

2. Physical examination to confirm weight, temperature, and, where relevant, eyes and neurological status.

3. Observation period after the final dose, during which your cat is watched for any return of signs.

4. Follow-up testing during observation, at intervals your veterinarian sets.

Only after your cat holds steady through this period will your vet describe the disease as being in remission. We are clear about what the data shows and what it does not: remission is confirmed by evidence over time, not declared on the last injection day.

What should you do after treatment to protect remission?

After Feline Infectious Peritonitis (FIP) treatment, protect remission by completing every prescribed dose, attending all follow-up checks, feeding well, and reducing stress so your cat can rebuild strength. The weeks right after the final dose are when careful observation matters most.

Supporting appetite is a big part of this. Our practical guides on appetite support for cats with FIP and supporting your cat's recovery after FIP treatment offer feeding and care ideas for this stage.

If any old signs reappear during or after the observation period, contact your veterinarian promptly. Understanding why FIP relapse happens and what to do helps you act early rather than wait.

FAQ

Is remission from Feline Infectious Peritonitis (FIP) the same as being cured?

Remission from FIP means the disease is inactive and your cat is clinically well after completing treatment and an observation period. It is confirmed by your veterinarian through resolved signs and stable bloodwork, and it is monitored over time rather than declared on a single day.

How long after the 84-day protocol is Feline Infectious Peritonitis (FIP) considered to be in remission?

After the 84-day GS-441524 protocol, your veterinarian typically watches your cat through an observation period before confirming Feline Infectious Peritonitis (FIP) remission. The exact length and testing schedule are set by your vet based on your cat's form of FIP and how the bloodwork trends.

What bloodwork shows Feline Infectious Peritonitis (FIP) remission?

Bloodwork suggesting FIP remission includes globulin and the albumin-to-globulin ratio returning toward normal, recovering red cell counts, and normalizing bilirubin where it was elevated. Your veterinarian compares these against your cat's baseline results to judge recovery, so consistent testing throughout treatment is important.

Can Feline Infectious Peritonitis (FIP) come back after remission?

Yes, FIP can return after remission, which is why completing the full protocol and attending follow-up checks matters so much. If earlier signs reappear, contact your veterinarian promptly so they can reassess and advise on next steps.

Does the form of Feline Infectious Peritonitis (FIP) change how remission is confirmed?

Yes. Wet FIP remission is often tracked by clearing fluid, dry FIP by bloodwork and organ signs, ocular FIP by eye examination, and neurological FIP by coordination and behavior. Because these forms carry different GS-441524 doses, from 6 mg/kg for wet up to 10 mg/kg for ocular and neurological, your veterinarian tailors both treatment and confirmation to the form.

Reaching remission is a milestone worth understanding fully, and you do not have to navigate it alone. To explore the GS-441524 treatment options in detail and talk through your cat's stage of recovery, connect with the CureFIP Oceania team and keep your own veterinarian involved in every decision along the way.