Infectious laryngotracheitis (ILT) is an acute, highly contagious, herpesvirus infection of chickens and pheasants characterized by severe dyspnea, coughing, and rales. In the acute form, gasping, coughing, rattling, and extension of the neck during inspiration are seen 5–12 days after natural exposure. Reduced productivity is a varying factor in laying flocks. Affected birds are anorectic and inactive. The mouth and beak may be bloodstained from the tracheal exudate.