Feline Infectious Peritonitis (FIP) – What to Do? Symptom Recognition and Scientific Treatment Guide

Introduction

Feline Infectious Peritonitis (FIP) is one of the most serious diseases affecting cats worldwide. For many years, it was considered almost always fatal, leaving cat owners and veterinarians with limited options. However, with the development of advanced antiviral therapies, particularly GS-441524-based treatments such as Pronidesivir (NeoFipronis®), there is now real hope for cats diagnosed with FIP. This guide will help cat owners understand how to recognize symptoms early, what steps to take, and how modern treatment can change the outcome for their pets.

1. Understanding FIP

FIP is caused by a mutation of the feline coronavirus (FCoV). While FCoV is common in multi-cat environments and usually harmless, in a small percentage of cats the virus mutates into a dangerous form that spreads through immune cells. This leads to severe inflammation throughout the body, damaging vital organs and causing progressive illness.

2. Symptoms of FIP

Recognizing the signs of FIP early is critical for starting treatment as soon as possible. Symptoms can vary depending on whether the disease presents as wet (effusive) or dry (non-effusive) FIP.

  • General symptoms: persistent fever, loss of appetite, weight loss, lethargy

  • Wet FIP: fluid build-up in the abdomen or chest, causing a swollen belly or difficulty breathing

  • Dry FIP: neurological signs such as seizures, imbalance, or paralysis; eye problems like uveitis, cloudiness, or vision loss

  • Mixed forms: some cats show both fluid accumulation and neurological or ocular signs

    3. What to Do if You Suspect FIP

  • Seek veterinary care immediately: FIP shares symptoms with other diseases, so professional diagnosis is necessary

  • Diagnostic tests: blood tests may show anemia, abnormal protein levels, or high globulins; imaging (ultrasound, X-ray) can reveal fluid; fluid analysis and PCR tests may help confirm suspicion

  • Do not delay: FIP can progress rapidly, and early intervention improves treatment outcomes

    4. Scientific Treatment Options

    Until recently, FIP was considered incurable. Today, antiviral drugs have changed the landscape.

  • GS-441524 and Pronidesivir (NeoFipronis®): these drugs directly inhibit viral replication, offering survival rates above 80–90% when used properly

  • Treatment duration: standard courses last around 12 weeks (84 days). Dosage is typically calculated at ~15 mg/kg/day, with higher doses required for neurological or ocular involvement

  • Supportive care: nutritional support, fluid therapy, and supplements (such as taurine, omega-3 fatty acids, and antioxidants) can support recovery

    5. Prognosis

    With timely and proper antiviral treatment, most cats now have an excellent chance of recovery. Many cats return to normal lives after completing therapy, though follow-up exams are essential to monitor long-term health.

    6. Prevention

    While no guaranteed prevention exists, reducing exposure to FCoV can help

  • Keep litter boxes clean and minimize overcrowding in multi-cat households

  • Reduce stress, which can weaken immunity

  • Practice responsible breeding and cattery management

    Conclusion

    FIP no longer has to mean despair. With modern scientific treatments such as NeoFipronis® (Pronidesivir), early diagnosis and timely intervention can save lives. Cat owners should learn to recognize the symptoms, seek veterinary help quickly, and explore the available treatment options that bring real hope for their pets.