FIP in Cats: Costs for Testing and Treatment

What the work-up and treatment of FIP cost depends on the extent of the diagnostics, the cat's weight, and the duration of treatment. Since no surgery is involved, reimbursement is a matter of full illness cover.

What does suspected FIP cost: the honest answer first

There is no flat rate for suspected FIP, and reputable sources deliberately do not quote one. Feline Infectious Peritonitis is a disease triggered by the feline coronavirus, usually accompanied by fluid build-up in the abdominal or chest cavity. Its costs consist of three blocks that vary widely from cat to cat: the laboratory diagnostics, the medication dosed by weight, and the progress monitoring. Anyone promising you a fixed sum in 2026 is either calculating for a single case or calculating wrong.

• Diagnostics: general examination, fluid tap, ultrasound and laboratory values, billed according to the fee schedule for veterinarians (GOT).
• Medication: the antiviral GS-441524, dosed by body weight over a treatment period of several weeks.
• Progress monitoring: follow-up examinations and laboratory checks throughout the entire treatment period, initially also on an inpatient basis in the study setting.

Why no fixed prices? Body weight determines the amount of medication, the form of FIP (with or without fluid build-up, dry or wet) determines the extent of the diagnostics, and the course of health determines how long monitoring continues. On top of that: the GOT fee schedule has no fixed prices, only a range from the simple to the triple rate, which the practice fills in depending on effort and circumstances.^[1]

An important change has altered the situation: since early 2025, Germany has had the legal basis for treatment based on GS-441524. The Veterinary Association of Hesse has approved the sourcing of corresponding preparations through a pharmacy on veterinary prescription.^[2] What the therapy actually costs, however, remains a case-by-case calculation. And one thing upfront: whether and how your cat is treated is decided by the veterinarian — this article is no substitute for veterinary advice.

Diagnostics: why there is no single FIP test

The first surprise for many owners: there is no single confirmatory test for FIP. The diagnosis relies on detecting the feline coronavirus via RT-PCR or RT-qPCR — a laboratory method that detects and amplifies viral genetic material in a sample — in combination with typical clinical and laboratory findings. The virus alone proves nothing: very many cats carry the feline coronavirus without ever developing FIP.^[3]

The so-called mutation test advertised commercially is also no proof. In a study of 63 cats with clinical suspicion of FIP, a commercial RT-PCR mutation test achieved a sensitivity of only 68.6 percent in effusion fluid, with a specificity of 95.8 percent — meaning roughly one third of FIP cases went undetected.^[4][5] A negative test therefore does not rule out FIP, and a positive one does not replace the overall assessment. That is why the diagnostic work-up is always a package of several components.

• General examination including consultation and medical history
• Imaging, typically ultrasound of the abdominal or chest cavity
• Tapping: targeted removal of effusion fluid with a needle; the fluid obtained is called the aspirate
• Laboratory analysis of the aspirate and blood values, e.g. protein ratio, inflammation and blood count parameters
• Molecular virus detection via RT-qPCR in the aspirate as one component among others

For your bill, this means: no line item reading "FIP test" appears on it, but rather a series of individual GOT services. That is precisely why the diagnostics block can only be quantified once it is clear which steps are necessary in the individual case.

What diagnostics actually cost: a worked example based on the GOT

The GOT is the fee schedule for veterinarians, a nationwide statutory regulation that has applied in its current version since 22 November 2022. It sets a minimum rate for each service that must not be undercut and allows a range of up to three times that rate; in emergency service, the two to four times rate applies plus a 50 euro emergency service fee. Which rate level the practice applies depends, at its reasonable discretion, on difficulty, time required, timing, the value of the animal and local conditions.^[1]

A worked example at the minimum rate: general examination €23.62, ultrasound €58.92 and one follow-up examination €19.74 add up to €102.28 net.^[1] Tapping the abdominal or chest cavity and the laboratory analysis of the aspirate come on top as separate fee items; laboratory shipping and PCR charges are billed separately. All fees are subject to 19 percent VAT. If the practice applies the double or triple rate, the same fees double or triple accordingly; in emergency service, the emergency service fee is added. Diagnostics alone can therefore run into the low hundreds of euros or well above, depending on scope and rate level.

Medication and progress monitoring: GS-441524 by weight

The largest cost block is the medication. GS-441524 is not approved as a ready-to-use medicinal product; it can be prescribed as a formula magistralis, i.e. a preparation that a pharmacy produces individually on veterinary prescription.^[2] Specifically, according to the Veterinary Association of Hesse, a pharmacy in France prepares an oral paste containing GS-441524 and ships it on prescription. Prescription takes place exclusively on a case-by-case basis by the veterinarian; sourcing routes are their responsibility, not part of self-treatment.

How expensive this block becomes is decided by two factors: the cat's weight, which determines the daily dose, and the number of treatment days. A prospective, randomized study from Munich showed that 42 days with 15 mg of GS-441524 per kilogram of body weight daily is just as effective as the previously standard 84-day regimen.^[3] In the study, the cats were treated inpatiently for the first seven days and then presented at the clinic regularly. Whether this regimen applies in your individual case is decided by the treating practice; a cure guarantee is not included in any study, and certainly not in this article.

• Medication: dose by weight times treatment duration, plus pharmacy fee and shipping, billed separately from the GOT scale of fees
• Follow-up examinations: at the simple rate 19.74 euros per appointment, several times over the weeks
• Laboratory checks: blood panels to monitor progress, simple rate 20.80 euros for the small and 23.52 euros for the large machine blood panel^[6]
• Inpatient initial phase: depending on the course, days at the clinic, boarding from 11.45 euros per day excluding treatment costs

The total only becomes reliable for your case once the practice draws up a cost plan after the diagnostics, adding up medication, follow-up examinations and laboratory checks over the entire treatment period.

Surgery cover or full illness cover: who reimburses FIP costs

Now for the distinction that decides your case. FIP almost never causes surgery costs. A cat surgery insurance policy, however, only pays for medically necessary operations including preliminary examinations and aftercare. Diagnostics and medication without surgery fall through the cracks with it. They are only eligible for reimbursement under full illness cover, which includes medically necessary treatment for an illness, including prescribed medication. That is precisely why FIP is the case where pure surgery cover is of no use.

The Consumer Advice Centre Hamburg sums up the state of the market: a pet health insurance policy reimburses vet and surgery costs for outpatient, inpatient and surgical treatments, medication and diagnostics, usually with a deductible of around 20 percent and a waiting period of three months from the start of the policy; only in the case of accidents does cover apply immediately.^[7] Two restrictions come with this: many tariffs only reimburse up to twice the GOT rate, and ongoing or acute treatments cannot be insured retrospectively. We have explained in detail how waiting periods work separately.

• Is treatment without surgery expressly included, or only the surgical procedure?
• Are medications prescribed by the vet eligible for reimbursement?
• Up to which maximum GOT rate is reimbursed — simple, double or triple?
• What are the reimbursement rate and deductible per claim?
• What waiting period applies to illnesses, and are there exclusions for pre-existing conditions?

Check these five points against your insurance documents before you hope for reimbursement. If you are looking for full cover that includes diagnostics, treatment and medication, compare the tariffs for cat health insurance and calculate your premium directly online. Whether your specific tariff will still reimburse an ongoing FIP treatment is something only the insurer can tell you based on your policy.

Outlook and next step

What is certain today: therapy with GS-441524 is legally possible via the pharmacy on prescription, and the study evidence supports the shortened regimen described above. What remains open: the legal situation for FIP medicines and the treatment regimens are constantly changing, and how future prices or rules will develop cannot be quantified. So do not extrapolate today's amounts onto future rules.

The question of reimbursement remains: whether your case is covered is decided by your specific tariff, and a general article cannot settle that individual case. The next step is yours: check your documents against the checklist above, or compare the tariffs for surgery cover or full cover if you are still weighing up the decision.

If full cover is the right choice for you: the cat health insurance policies that nextsure brokers reimburse, depending on the terms, medical treatments, surgery, diagnostics and physiotherapy up to the agreed maximum GOT rate, either as health cover or as combined health and surgery cover. You compare the tariffs transparently, receive independent advice and complete the whole process digitally. Calculate your premium now and see which cover really pays off for your cat in a case like FIP.