Feline coronavirus is a common virus of both domestic and non-domestic felids. In a small percentage of infected felines, a fatal systemic disease, feline infectious peritonitis (FIP), develops. Diagnosis of FIP, as well as management of coronavirus infection in multi-cat environments, is hampered by the fact that no assay specific for the virulent form of the virus exists. Identification and removal of chronically infected cats may be desirable in multi-cat environments. The researchers will investigate the correlation of 7b protein expression (indicated by the presence of the specific antibody) with chronic virus shedding. If a correlation exists, testing for 7b-specific antibody would offer a quick and reliable method for identification of persistently infected animals, aiding management of multi-cat situations to reduce the risk of FIP.