How much does FIP treatment cost?

Short answer: there is no single price. FIP treatment cost is driven by four things — your cat's weight, the drug and route, the FIP form, and the 84 days of monitoring around the antiviral. A bigger cat, a neurological case, or a fully regulated legal supply all push it up. Anyone quoting one flat figure is guessing at your cat.

Cost is one of the hardest parts of an FIP diagnosis, and it deserves an honest answer rather than a number pulled from the air. Here is what actually moves it.

The four cost drivers

• Weight. Antiviral dose is per kilogram, so a 6 kg cat costs roughly twice the drug of a 3 kg kitten across the same course. Weight is usually the single biggest lever. See how it scales in the dosage calculator.
• FIP form and severity. Ocular and neurological FIP need higher doses to reach the eye and brain, so they cost more per day than mild dry FIP.
• Drug and route. Injectable vs oral, and GS-441524 vs remdesivir vs molnupiravir, all price differently. Legal, regulated preparations (UK/Australia, or US compounded-on-prescription) generally cost more than the unregulated market — but that price buys a tested product and veterinary oversight.
• The 84 days around the drug. Diagnosis, baseline bloodwork, and repeat monitoring across the course are a real part of the bill — and skipping them is a false economy.

Why the cheapest option is rarely the cheapest

The unregulated market is where the lowest headline prices live — and where the quality problem lives too. Independent testing found unlicensed products containing far less drug than labelled, which risks under-dosing, a longer course, resistance, or a failed treatment. A cheaper vial that doesn't cure is the most expensive outcome of all.

What to budget for, honestly

• The antiviral course (weight × dose × 84 days × drug price).
• Diagnosis and monitoring — the vet visits and bloodwork that confirm FIP and track recovery.
• A buffer for the watch period and the possibility of relapse, which can mean re-treatment.

The most useful thing you can do before pricing anything is get a clear diagnosis and a dose from your vet — then the numbers become concrete instead of frightening. Start with what FIP is and the treatment evidence.

Not veterinary advice. Prices vary by country, supplier, and cat; your vet is the right source for a real quote.