FCoV (Feline Coronavirus) belongs to the Coronaviridae family, an enveloped virus with a single-stranded positive-sense RNA, containing key proteins such as spike, membrane, envelope, and nucleocapsid. It primarily replicates in feline intestinal cells and can cause enteritis. Mutations may lead to Feline Infectious Peritonitis (FIP), a severe fatal disease. FCoV manipulates host immune responses, affecting its survival and transmission.