Feline Infectious Peritonitis: Diagnosis and
Veterinarian Jillian Myers Smith outlines a diagnostic algorithm and treatment options for feline infectious peritonitis (FIP), emphasizing the need to
Veterinarian Jillian Myers Smith has detailed a clinical approach for diagnosing and treating feline infectious peritonitis (FIP). Timely diagnosis is critical, as antiviral medications now make successful outcomes common when treatment starts early, according to the source.
Before testing for FIP, clinicians must rule out other conditions that mimic it. Using antivirals for suspected FIP without assessing for other differentials is inappropriate. Once other possibilities are eliminated, a treatment trial with antiviral drugs may be considered for cases with high suspicion but no confirmed diagnosis. A recheck of the cat's response is recommended within a few days. If there is no improvement, other differentials must be investigated.
Diagnostic Scoring Systems
Using expert-developed scoring systems can help gauge the likelihood of FIP. The Brisbane score provides quantitative diagnostic criteria to assess an individual patient. The European Advisory Board on Cat Diseases has also developed diagnostic scoring systems for suspected FIP.
Treatment Options
After a definitive diagnosis or with strong suspicion and appropriate clinicopathologic findings, treatment should begin quickly. Two antiviral classes are used: nucleoside analogues and protease inhibitors. Nucleoside analogues, including remdesivir, its active metabolite GS-441524, molnupiravir, and its metabolite EIDD-1931, are the most well-studied and have proven safety and efficacy. Protease inhibitors like nirmatrelvir-ritonavir and GC376 may have efficacy as add-on treatments or for refractory cases, but more research is needed.
| Antiviral Class | Examples | Notes |
|---|---|---|
| Nucleoside Analogues | remdesivir, GS-441524, molnupiravir, EIDD-1931 | Most well-studied; proven safety and efficacy for FIP. |
| Protease Inhibitors | nirmatrelvir-ritonavir, GC376 | May be used as add-on or for refractory cases; more research needed. GC376 is not commercially available. |
Treatment Monitoring and Course
Monitoring should minimize costs and stress. If a cat is improving based on owner check-ins, follow-up tests can be done 3 to 4 weeks after starting treatment. Focus should be on previously abnormal values like hematocrit or bilirubin. Albumin and globulin normalization may take several weeks. Evaluation of basic parameters like a CBC and serum biochemistry panel at 6 and 12 weeks is recommended. This adjusts to 3 and 6 weeks if using a 42-day treatment course.
The source encourages readers to explore extensive online reviews for more detail, as FIP presentation is variable. The algorithm focuses on when and how to treat the disease. For comprehensive data on treatment protocols, veterinary professionals can review our stats page. Case management often involves tracking a patient's injuries and recovery timeline.
