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Recovery

What to expect and record during treatment

Written by
FIP Together editorial team
Based on
3 published sources
Published
16 Oct 2026
Updated
17 Oct 2026

A typical timeline

  • Within a few days: fever and general signs often start to improve, and appetite returns. Surviving the first days of treatment is itself a good sign.
  • Around two weeks: fluid and jaundice usually clear, and red blood cell levels start to rise.
  • Several weeks: globulin levels and the A:G ratio can take weeks to normalise. Eye inflammation can also take weeks to settle fully.

Don't be alarmed by one expected blip: in some cats with wet FIP, weight can drop and globulins rise around two weeks as fluid is reabsorbed. This doesn't mean treatment is failing, but do tell your vet.

Checks your vet may suggest

  • A call or check about 48 hours after starting.
  • A review at about two weeks, including whether fluid has reduced.
  • Blood tests at two weeks and then roughly monthly, and normal results before stopping.
  • AGP (inflammation marker): two normal results a week or two apart help confirm recovery.

What to record at home

  • Weight every week or two on baby or kitchen scales. Rising weight is encouraging, and the dose may need adjusting.
  • Appetite, energy, mobility, litter tray, vomiting or diarrhoea.
  • Temperature only if your vet has shown you how.
  • A daily photo: changes in coat, posture and alertness are easier to see side by side.

Charts in FIP Together show what you recorded. They don't judge recovery; your vet does.

Sources

  1. European Advisory Board on Cat Diseases (ABCD). Guideline for Feline Infectious Peritonitis, updated March 2026.
  2. Effect of nucleic acid analog administration on fluctuations in the albumin-to-globulin ratio in cats with FIP. 2024.
  3. European Advisory Board on Cat Diseases. Update on Treatment of Feline Infectious Peritonitis: ABCD Guidelines. Viruses. 2026;18(4):452.

This guide summarises published veterinary guidelines and research for owners. It is general information, not veterinary advice, and can't account for your cat's situation. Always follow the guidance of the veterinarian treating your cat.