Update on the treatment of FIP with antiviral drugs in 2025 (Bova)

On July 3, 2025, Bova published updated recommendations for the treatment of FIP with various antiviral drugs. It should be noted that the recommended injection dosage of GS-441524 is missing, as Bova does not produce this active ingredient in injectable form.

Bova is a manufacturer of legal FIP medication, although very few veterinarians in the Czech and Slovak Republics use it due to its high price.

Feline infectious peritonitis (FIP) was until recently considered a fatal disease of cats with no effective treatment. However, since 2020, there has been a major breakthrough in the treatment of FIP with the legal availability of antivirals such as remdesivir and its active metabolite GS-441524, initially in Australia and the United Kingdom. This expert review summarizes current recommendations for veterinarians regarding the diagnosis, treatment and monitoring of patients with FIP, and presents the growing clinical experience with individual therapeutic approaches.

The treatment focuses on nucleoside analogues (GS-441524, remdesivir, molnupiravir/EIDD-2801, EIDD-1931), whose mechanism of action is based on the inhibition of viral RNA replication. Oral administration of GS-441524 has been shown to be highly effective even as monotherapy, including in neurological and ocular forms of FIP. The recommended duration of treatment is 12 weeks (84 days), although a shorter 6-week regimen may be considered in cases of early diagnosis and rapid clinical response. Dosage must be adjusted to the individual patient's condition, type of FIP, absorption of the active substance and possible weight gain during treatment.

The document also discusses in detail the possible adverse effects of antiviral drugs (e.g. neutropenia, ALT elevation, gastrointestinal symptoms), recommendations for use in specific cases, and emphasizes the importance of therapeutic monitoring using acute phase proteins (AGP, SAA) and albumin/globulin ratio monitoring. A key caveat is the use of unregulated preparations that may be toxic and of unclear active substance content.

In addition to primary treatment, attention is paid to relapse management, supportive care (including nutrition, analgesia, antiemetics), as well as comorbidities such as immune-mediated hemolytic anemia (IMHA) or myocarditis. Owner support in home care, correct weight-based dosing, and appropriate education are essential for a successful treatment outcome.

In conclusion, FIP now appears to be a treatable disease, with long-term survival rates exceeding 90% with early diagnosis, appropriate treatment, and good compliance, thanks to the availability of quality antivirals and comprehensive management. The aim of this document is to support veterinarians in their professional confidence in the treatment of FIP and to increase the availability of effective treatment for affected cats worldwide.

For those who are only interested in the treatment protocol itself, I am attaching a clear table.

Below you will find the full article in PDF format in English.