4 Key Tests to Determine if Your Cat Has FIP
If you suspect your cat may have Feline Infectious Peritonitis (FIP), early diagnosis is extremely important. However, diagnosing this disease is not always simple. No single test can confirm FIP with 100% certainty — veterinarians combine different tests to evaluate symptoms, blood markers, and tissue samples to determine the probability of FIP infection more accurately.
Below are the four important diagnostic tests commonly used by veterinarians. For a deeper breakdown of each test and what the results mean, read our complete guide to the 4 FIP diagnostic tests.
1. Antibody Titre Test
The Antibody Titre Test measures the level of antibodies present in a cat’s blood. These antibodies form when the immune system reacts to viruses such as the feline coronavirus. A higher antibody level may indicate that the cat has been exposed to the virus. However, this test alone cannot confirm FIP — it is used as an early indicator during the diagnostic process.
Key points:
- Measures antibody levels in the bloodstream
- Helps detect exposure to feline coronavirus
- Often used during early diagnostic stages
2. Histopathological Examination
The Histopathological Examination is considered one of the most accurate methods used to confirm FIP. Veterinarians collect tissue samples from affected organs, which are then processed, sliced into thin sections, and stained with special dyes. A veterinary pathologist studies the tissue under a microscope to reveal specific cellular changes linked to FIP infection.
This method includes:
- Surgical collection of tissue samples
- Laboratory tissue processing
- Microscopic analysis by veterinary specialists
3. Rivalta Test
The Rivalta Test is a simple diagnostic test commonly used to identify the wet form of FIP. Fluid is collected from the cat’s abdomen or chest cavity, then placed in distilled water mixed with acetic acid. If the fluid forms a jelly-like drop that sinks while retaining its shape, the result may indicate the presence of FIP-related proteins. The Rivalta test has a negative predictive value of approximately 96% — a negative result makes FIP very unlikely.
4. Comprehensive Blood Test
A Comprehensive Blood Test helps veterinarians assess several health indicators linked to FIP. This test examines:
- White blood cell count
- Red blood cell count
- Total protein levels
- Globulin concentration
- Albumin/Globulin (A:G) ratio — below 0.4 is strongly indicative of FIP
High globulin levels or a low A:G ratio may indicate inflammation caused by FIP. Blood test results are always combined with other diagnostic methods for a complete picture. Read our complete blood work guide for what each marker means during treatment.
Final Thoughts
Diagnosing FIP requires careful evaluation and multiple diagnostic methods. If you notice unusual symptoms in your cat, consult a veterinarian as soon as possible. Early detection can improve treatment options and recovery outcomes.
Once FIP is confirmed, GS-441524 treatment should begin immediately. Use our dosage calculator to get the correct dose for your cat’s weight and FIP form. Contact FIP Cure Plus for guidance on starting treatment.
The FIP Cure Plus team is available in English and Arabic at info@fipcureplus.com.
View the FIP Cure Plus GS-441524 20 mg/ml injectable →
View the FIP Cure Plus GS-441524 30 mg/ml injectable →
View the FIP Cure Plus GS-441524 oral capsules →
FIP Cure Plus — transparent, evidence-based GS-441524 treatment for cats across the Gulf.