Feline Infectious Peritonitis (FIP) is a serious and often fatal viral disease in cats caused by certain strains of the feline coronavirus. It primarily affects young cats or those with weakened immune systems. FIP manifests in two forms: “wet” (effusive), characterized by fluid accumulation in the abdomen or chest, and “dry” (non-effusive), which involves granulomatous inflammation in organs. Symptoms include fever, weight loss, lethargy, and loss of appetite.