The science behind the FIP cure
Dr. Niels Pedersen's studies at UC Davis changed everything in 2019. Here is a summary of the most relevant research that transformed the prognosis of this disease.
Dr. Niels Pedersen: UC Davis, 2019
The first clinical trial to show that GS-441524 could cure FIP in cats with confirmed naturally occurring disease. This study in 31 cats set the basis of modern treatment and the dosing guidance still in use today.
View the study en PubMednaturally occurring FIP
adjusted doses
prognosis changed
Key studies
The published evidence behind antiviral treatment for FIP.
Efficacy and safety of the nucleoside analog GS-441524 for treatment of cats with naturally occurring feline infectious peritonitis
Clinical study in 31 cats with confirmed naturally occurring FIP. 26% of the cats showed a complete response at low doses; once doses were raised, the response rate passed 80%. The starting point of every modern protocol.
Efficacy of a 3C-like protease inhibitor (GC376) and a nucleoside analogue (GS-441524) for treating FIP
The first study comparing GC376 and GS-441524. Both compounds showed antiviral activity; GS-441524 gave better results in naturally occurring cases, laying the ground for the current standard of treatment.
Molnupiravir antiviral activities against feline infectious peritonitis virus in vitro and in vivo
The first solid clinical demonstration of molnupiravir (EIDD-2801) working in cats with naturally occurring FIP, including neurological and ocular forms. It opens an oral alternative where access to GS-441524 is limited.
ABCD guidelines on prevention and management of feline infectious peritonitis
The official update of the European ABCD guidelines, recognising the antivirals GS-441524 and GC376 as the standard treatment for FIP. The first institutional European acknowledgement of their efficacy.
Papers and studies to download
Reference documents for vets and owners who want to go deeper into the scientific evidence.
89 FIP cases treated with GS-441524
A retrospective analysis of 89 cats diagnosed and treated with GS-441524 in Spain. It covers dosing, duration, clinical response and post-treatment follow-up.
GS-441524 for treatment of cats with naturally occurring FIP
The seminal UC Davis study (2019) in 31 cats that established the efficacy of GS-441524 and the basis of the modern dosing protocol.
A review of feline infectious peritonitis virus infection
An updated review of the pathogenesis of FIPv: how the feline enteric coronavirus mutates and drives the systemic inflammatory response that defines FIP.
Molnupiravir antiviral activities against FIP virus in vitro and in vivo
A study published in the Journal of Veterinary Internal Medicine (2023) demonstrating the efficacy of molnupiravir in naturally occurring FIP. It includes dosing data and response in neurological forms.
A systematic review of GS-441524 and GC376 for FIP treatment
A systematic review published in MDPI Animals synthesising the available evidence on GS-441524 and GC376, including cure rates, adverse effects and a comparison between clinical forms.
Links to external studies point to PubMed or to the original journals. The PDF of the Spanish study by Dr. Vicky Vives is downloaded directly from this site.
The scientific evidence
What the studies consistently show about antiviral treatment for FIP.
Survival rate in cats treated with GS-441524 according to Pedersen et al., with doses adjusted to the form of FIP.
The minimum treatment duration set in the clinical protocols derived from the UC Davis studies, for both wet and dry forms.
The studies confirm both routes work, with the dose adjusted for the difference in bioavailability (oral is around 50% of injectable).
High-dose GS-441524 (≥10 mg/kg SC or ≥20 mg/kg oral) works even when the virus crosses the blood-brain barrier.
The European ABCD guidelines formally recognise antivirals as the standard treatment for FIP, consolidating the evidence gathered since 2019.
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