Virus pneumonia of pigs (VPP) is an inflammation of the lungs usually confined to the anterior-ventral portion and lower borders of the apical and cardiac lobes. It is usually a chronic disease that may develop into acute and subacute forms, particularly if "secondary break down" occurs due to secondary bacterial invasion. The disease is characterized by a chronic cough, consolidation of the anterior ventral portions of the lung, and secondary bacterial invasion. It is a distinct disease and is in no way related to the common swine influenza described by Shope in 1931.