Ocular FIP treatment enters a more practical era

Ocular FIP is getting renewed attention as feline infectious peritonitis treatment moves from improvised protocols toward more standardized, veterinarian-directed care. In the VetGirl podcast coverage, Dr. Justine Lee highlights newer evidence around antiviral therapy for ocular disease, a form of FIP that has historically been harder to treat because the blood-eye barrier can limit drug penetration. The podcast also underscores that ocular signs may be the main presenting feature in some cats, with findings such as uveitis, keratic precipitates, iris color change, anisocoria or dyscoria, hyphema, hypopyon, fibrinous exudate, retinal hemorrhage, retinal detachment, and perivascular retinal cuffing helping raise suspicion for systemic FIP. Published clinical data support the treatment challenge: in one Journal of Veterinary Internal Medicine series, cats with ocular or neurologic FIP were started at higher remdesivir or GS-441524 doses than uncomplicated cases, and 4 of 6 cats with ocular involvement recovered fully. Since June 1, 2024, U.S. veterinarians have also had access to compounded oral GS-441524 by prescription under FDA enforcement discretion, changing how readily these cases can enter supervised treatment. (academic.oup.com)

Why it matters: For veterinary professionals, ocular FIP is no longer a fringe, near-hopeless presentation. It’s increasingly a treatable condition, but one that still demands careful case selection, dosing, and follow-up. Available guidance suggests ocular and neurologic cases often need higher dosing than non-ocular disease, with dose adjustments tied to clinical response, body weight changes, and the practical realities of long treatment courses. VetGirl’s related coverage on dosing and duration also notes why clinicians are looking for more objective ways to decide when therapy can stop: many cats improve clinically within the first week, but that early response does not necessarily mean viral clearance, especially in harder-to-penetrate tissues like the eye and CNS. Acute phase proteins such as serum amyloid A and alpha-1 acid glycoprotein, along with the albumin:globulin ratio, are being studied as treatment-monitoring tools, though not yet as a simple shortcut for ocular cases. Experts also caution that emerging data on shorter 42-day protocols were driven mainly by effusive FIP and shouldn’t yet be broadly extrapolated to ocular cases. (academic.oup.com)

What to watch: Expect more discussion around whether ocular FIP can safely move to shorter treatment durations and whether biomarkers can help guide treatment termination more confidently, but for now, most expert-facing guidance still supports individualized, often higher-intensity antiviral protocols with close monitoring. (wormsandgermsblog.com)