Hemorrhagic tracheitis associated with swine influenza virus in a show pig

A crossbred show pig from Oklahoma presented with respiratory distress, coughing, and culmination of rapid progression to death. Postmortem examination revealed segmental hemorrhagic tracheitis with luminal narrowing from submucosal hemorrhage and histopathology confirmed ulcerative tracheitis and bronchointerstitial pneumonia. Polymerase chain reaction detected swine influenza virus in both the trachea and lungs. Swine influenza virus is a recognized component of the porcine respiratory disease complex and its association with hemorrhagic tracheitis suggests a potential role in hemorrhagic tracheitis syndrome. This Oklahoma case highlights the need for greater awareness and surveillance of this underrecognized condition.