Summary of Section 7: Diagnosis of FIP; Section 7.1: Signalment and History for FIP  FIP is more common in young cats (especially under two years old) and some pedigree breeds, and male cats are at slightly higher risk of disease. Additionally, most cats that develop FIP come from multi-cat households or have a history of having been housed in multi-cat households. A recent history of stress (e.g., adoption, being in a shelter, neutering, upper respiratory tract disease, vaccination) is common.