Medical Manual

What is FIP?

Feline Infectious Peritonitis (FIP) is a severe immune-mediated disease caused by a mutated form of feline coronavirus (FCoV).

Most cats carry the benign form of FCoV with no symptoms. However, when the virus mutates inside the body, it can trigger an abnormal immune reaction that leads to widespread inflammation affecting major organs such as the liver, kidneys, intestines, and central nervous system.

Without treatment, FIP progresses rapidly and is almost always fatal. Early detection and early intervention are critical, as timely treatment can prevent organ failure and dramatically improve survival outcomes.

What is GS-441524 and How Does It Work?

GS-441524 is a nucleoside analog that blocks the replication of FIP virus inside infected cells.

It has become the global standard for FIP treatment due to its:

• High efficacy across all FIP forms
• High safety margin compared to older therapies
• Predictable pharmacokinetics
• Strong performance in real-world clinical data

Veterinarians and treatment centers worldwide now rely on GS-441524 as the primary frontline therapy for FIP.

Types of FIP and Symptoms

In the early stages, cats may show subtle changes such as behavioral shifts, weight loss, reduced appetite, and fluctuating fevers. These symptoms can be easy to miss. Your cat may seem less social than before, preferring to hide or sleep more often. Pica-eating non-food items-is another behavioral change associated with the virus and can sometimes be an early sign of FIP.

Below are common symptoms seen in different forms of FIP:

LATE-STAGE FIP SYMPTOMS

As FIP progresses, symptoms may worsen and lead to organ failure-one of the most severe outcomes of the disease. FIP is an inflammatory condition that can affect multiple organs, including the kidneys and liver. In advanced stages, this inflammation can result in significant organ dysfunction or complete organ failure.

Treatment Process (84 Days)

The standard GS-441524 treatment course lasts 84 days. Medication must be given daily at roughly the same time.

Dosage is calculated based on your cat's weight and symptoms, so please weigh your cat weekly and adjust the dose accordingly. If you are unsure about dosage, contact our online support team.

Throughout treatment, it is recommended to schedule monthly blood tests (CBC + chemistry panel) and submit the results to our Facebook group admins. Our team will check for potential FIP-related complications and advise on supplements when needed.

Before completing treatment, please submit your Day 80 blood test via Facebook Messenger. Our veterinary team will review the results. Once approved, you may stop treatment on Day 85 and enter the 84-day observation period.

During observation, minimize stress and monitor your cat closely. One to two follow-up blood tests are recommended (but not required). If no relapse occurs by the end of observation, your cat can be considered fully recovered.

Dosage Guidelines

Doses must always be calculated using the cat's current body weight and adjusted as the cat gains weight.

Injectable Dosage (SC, once daily):

Oral Tablets (PO):

Oral dosages are higher due to lower bioavailability.

* Twice-daily (q12h) administration is required for high-dose or neurological cases.

Injection vs. Oral Tablets

GS-441524, the main therapy for FIP, comes as injections or oral tablets. Both can achieve up to 98% cure rate with correct dosing and administration.

Clinical guidance:

• Start with injections, especially for acute or severe cases.
• Switch to oral tablets once the cat stabilizes (normal appetite, elimination, no fever).
• Choice depends on the cat's health, GI condition, and tolerance.

Hybrid Approach (Most Common):

Start with injections for 3-7 days in severe cases, then switch to oral tablets once the cat stabilizes.

When to Switch from Oral Back to Injection

Switch to injectable GS-441524 if any of the following occur:

• Persistent vomiting (oral absorption becomes unreliable)
• Severe diarrhea
• Sudden neurological deterioration
• Worsening clinical signs despite correct oral dosing
• Unstable lab results

Injections provide rapid and predictable drug absorption in these cases.

Common Side Effects of FIP Treatment

During FIP treatment, some cats may experience mild side effects such as reduced appetite, slight vomiting, or diarrhea.

Because FIP medication can place some stress on the liver and kidneys during the treatment, we usually recommend adding liver and kidney support supplements (such as liver protectants, renal support, or probiotics) to help your cat recover more smoothly.

The MaxPaw team will provide one-on-one guidance based on your cat's condition, ensuring a safe and steady treatment journey.

Supportive Care & Supplements

MaxPaw is the only brand that has invested extensive laboratory research into developing supplements specifically for cats with FIP. During both treatment and recovery, our formulations are designed to support liver, gastrointestinal, and immune health, ensuring therapeutic support without interfering with GS-441524 absorption.

Most commercial cat supplements are designed for "healthy cats," but FIP cats have very different needs. During treatment, common challenges include:

• Elevated liver enzymes (ALT/AST)
• Reduced appetite
• Digestive instability and soft stools
• Immune fatigue
• Metabolic burden from long-term medication

Standard supplements cannot meet these specific needs and may even interfere with GS absorption. That's why we developed professional FIP-specific supplements:

1. MaxPaw SAMePro 120 (Sources of liver stress: GS metabolism, Immune burden, Inflammatory responses, Weight and appetite fluctuations)

• Core ingredients: SAMe, Milk thistle (high Silybin content), NAC, Antioxidant complex.

• Key benefits: Helps stabilize ALT / AST, Supports liver metabolism, Improves appetite and vitality, Does not interfere with GS absorption (critically important).

2. MaxPaw FIPPro Biotics+ (For fragile gastrointestinal systems, soft stools, prone to diarrhea, chronic stress)

• Core Features: Does not compete with GS absorption, Triple biotics (contains postbiotics), Supports appetite, Improves stool quality, Enhances digestion and nutrient absorption.

Treatment Success Rate & Prognosis

FIP is no longer a death sentence. MaxPaw has helped 17,000+ cats recover from FIP with an overall success rate of over 98%. Most cats show improvement within 3 days when using injections, and tablet treatment typically shows results within 7 days.

You never have to face FIP alone - MaxPaw's 1-on-1 specialist support is here to guide you through every step, from symptom checks and dosing guidance to managing side effects, helping your cat confidently move toward recovery.

Preparing for Medication

Create a Calm Environment:

Choose a quiet, enclosed space such as a bedroom or bathroom. Remove distractions, close windows, and minimize loud noises. A calm environment reduces stress and makes medication easier for both you and your cat.

What to Prepare:

• A clean towel, Pill shooter or syringe, 3-5 ml clean water, Favorite treats, Gloves (optional).

Fasting Before Tablets:

If your cat tends to spit out medication, consider withholding food for 2-3 hours before dosing to increase cooperation.

How to Give Oral Tablets

The daily dose is determined by your cat's current weight and clinical symptoms. Weigh your cat weekly, monitor their condition, and adjust the dose as needed. Administer this dose once daily at a consistent time (within a 1-3 hour window).

If the daily dose exceeds 100mg, consider splitting it into two equal portions (morning and evening) to help maintain stable drug levels. For optimal absorption, administer the tablet on an empty stomach (at least 1 hour before or 2 hours after a meal). You may offer a regular meal 1-2 hours after administration.

Recommended Administration Methods:

• Pill Shooter: The recommended tool. It safely places the tablet at the back of the tongue for easy swallowing.
• Pill Wrap/Treat: Hide the tablet inside a commercial pill pocket or a soft treat. Ensure it is eaten immediately.

IF YOUR CAT REFUSES THE WHOLE TABLET:

1. Crush the tablet into a fine powder using a pill crusher.
2. Mix the powder with a very small amount (e.g., 1-2 mL) of water, low-sodium broth, or a tasty paste.
3. Administer the mixture using a feeding tube.

Important: Do not mix the medication into a full bowl of food or water. Incomplete consumption will result in an underdose, which can reduce treatment effectiveness and risk resistance.

How to Give Injections

The injections are given subcutaneously at about the same time every day (a flexible window of 1-3 hours is allowed for schedule adjustments). When opening the vials, please remove the plastic top and keep the metal cover on the edge, or the medicine may burst out due to air pressure.

Needle Management:

• Use two separate needles: one to draw up the medication and a fresh, sharp needle for the actual injection. This ensures a sharp point for less pain and tissue damage.
• Chilling the medication vial or syringe (not the needle) in the refrigerator for about 30 minutes prior to injection can help numb the site.

Anxiety & Pain Management:

• For very anxious cats, Gabapentin (requires a veterinarian's prescription) can be very helpful when administered prior to the injection.
• Consider shaving small areas at the planned injection sites and/or applying a topical lidocaine cream beforehand to numb the area and reduce the sting.

Injection Site Tips (Where to Inject):

• Always create a skin "tent" and insert the needle into the middle of the raised fold (Subcutaneous injection at 45 degrees into epidermis/dermis subcutaneous tissue, avoiding muscle).

• Subcutaneous injections can be given along the shoulders area, left and right of the spine (Zones L1, R1, L2, R2, L3, R3). For better visibility it's advised to shave the area.

• Do not inject in the cat's scruff, it's slow to absorb and the area is not big enough for all the injections. It can also cause scarring over time.

• Avoid if possible the butt's area, it's a particularly sensitive area, it can be more painful.

• If any medication leaks out after the injection, clean the skin immediately. Gently wipe the site afterward.

• Tools like a towel, blanket, cat sack (purrito method), or an Elizabethan collar (e-collar) can make the process safer and easier. Bribe your cat with a favorite treat before, during, or after.

Missed or Late Doses

If a dose is missed:

• Within 8 hours: Give immediately.
• Over 8 hours: Skip and resume the next day (do NOT double dose).

It is best not to interrupt treatment. If a break occurs, extend the treatment by the same number of missed days.

About MaxPaw

MaxPaw is a complete FIP recovery ecosystem, providing professional, reliable, and comprehensive support for every cat and owner. Since 2019, MaxPaw has grown from a brand simply providing reliable and safe GS-441524 into a complete FIP treatment ecosystem, offering:

• Veterinary Team Support: Vets help analyze complex symptoms, blood work, and neurological signs.
• 24/7 WhatsApp One-on-One Assistance: Immediate support for dosage calculation, appetite loss, vomiting/diarrhea, neurological assessment, multi-cat household guidance, relapse management, and emergency evaluation.
• Professional FIP Case Management: Weekly tracking of weight, symptoms, absorption, and treatment progress.
• Facebook Group Supervision & Support: Admins monitor cases; any issues are handled promptly with compensation if needed.

MaxPaw provides one of the deepest service levels in the GS-441524 market, ensuring your cat receives complete professional care throughout the recovery journey.

Local Pick-up Service

MaxPaw is proud to pioneer North America's first volunteer-driven Local Pick-up Service.

We understand that time is of the essence with FIP, and starting treatment now is key. That's why our network of over 500 compassionate volunteers—all experienced cat parents—is ready to provide you with timely access to medication, the moment you need it.

Our Lifetime Cure Guarantee

Cats improve in 1 Week with our FIP Treatment.

If your cat relapses during the observation period after 84 days of treatment, the MAXPAW team will provide GS-441524 vials for up to another 84 days at no cost.

MaxPaw Quality Assurance & QC Standards

MaxPaw maintains one of the strictest QC systems in the FIP treatment market:

• >99% Purity GS-441524: Certified lab grade.
• COA for Every Batch: Complete consistency and transparency.
• Every Milligram Accountable: Standardized production pipeline with accurate mg labeling.
• Optimized Oral Absorption Technology: MaxPaw Dual-phase release technology.

How to store GS-441524

Store GS-441524 tablets and vials at room temperature (68-77°F/20-25°C) and keep it away from direct sunlight and moisture.

When stored under these recommended conditions, the product has a shelf life of up to 2 years.

For injections, you may place the vial in the refrigerator for a short time before use. Lightly chilling the solution can help reduce injection discomfort and does not affect the medication's effectiveness.

Preventing FIP

Preventing FIP is difficult because feline coronavirus (FCoV) is extremely common, especially in multi-cat households. While FIP cannot be fully prevented, the following measures can lower risk:

1. Reduce Stress: Stress may trigger mutation of FCoV into FIP. Provide a calm, enriched environment with enough resources: food, water, resting areas, hiding spots, vertical space, scratching posts, and clean litter trays. Use the "1 per cat + 1" rule in multi-cat homes.

2. Maintain Good Hygiene (Scoop Daily, Disinfect Regularly): FCoV spreads through feces. Scoop litter daily, disinfect trays regularly, separate high-risk cats when needed, and avoid crowding around shared areas.

3. Responsible Breeding: Breeders should avoid breeding cats from FIP-affected litters, avoid breeding FIP-recovered cats, and avoid keeping large, dense cat groups.

4. Avoid Overcrowding: Keep cats in small, stable groups (preferably fewer than five). High-density environments increase FCoV transmission.

Frequently Asked Questions

Q1: Is FIP still a fatal disease?
No. With correct GS-441524 treatment, most cats fully recover and return to normal life.

Q2: Is oral GS-441524 as effective as injectable GS?
Yes—when properly formulated and correctly dosed. For mild cases, oral treatment is convenient and effective. For severe, neurological, or unstable cases, injectable GS is preferred.

Q3: Can my cat take supplements during treatment?
Yes. The right supplements can support liver function, gut health, and immune balance. MaxPaw provides a targeted FIP recovery nutrition system.

Q4: How do I know when to stop treatment?
Stopping treatment should be based on complete clinical recovery, stable blood work, and no new symptoms for several weeks.

Q5: Does my cat need a consolidation phase after 84 days?
Usually not. If very mild residual symptoms remain, extending treatment by 1-2 weeks may be recommended.

Q6: What is the relapse rate?
With correct dosing and a full 12-week course, relapse rates are below 5%.

Q7: What should I do if my cat relapses?
Most relapses can be fully cured with a second course, a higher dosage, and close monitoring. Relapse is treatable - do not panic.

Q8: My cat has no appetite. What should I do?
Many FIP cats lose weight and refuse food. Appetite stimulants, anti-nausea medication, or temporary feeding support (such as assisted feeding or a feeding tube) may be required.

Q9: Do injections cause pain?
Injection-site pain is common and expected. Use iodine for disinfection and apply hyaluronic acid gel to support skin repair.

Q10: Should dosage increase as my cat gains weight?
Yes. Whenever your cat gains 0.5-1 kg, dosage must be recalculated to maintain therapeutic effectiveness.

A Note to Veterinary and Clinical Partners

MaxPaw is committed to supporting veterinary clinics and professional partners with high-quality, reliable FIP care solutions.

Our products are formulated for stability, safety, and effectiveness, and are backed by a dedicated support team to assist with large-volume orders, logistics, and professional guidance. We provide educational resources, training, and consultation to ensure your team can confidently administer treatments and serve your clients. Partnering with MaxPaw means access to trusted products and expertise for the best possible outcomes for cats under your care.

FIP Bloodwork Reference Table

84-DAY FIP TREATMENT TRACKER Baseline Requirements:

* Submit your Day 30, Day 60, and Day 80 lab readings to your designated case manager for tracking and guarantee authentication.