Infectious laryngotracheitis is a highly contagious, economically important respiratory disease of poultry (especially chickens, peafowl, and pheasants) caused by a herpes virus which can result in severe production losses due to death and/or decreased egg production. Depending on viral strain, pathogenicity varies from mild conjunctivitis/sinusitis to severe respiratory difficulty and coughing up blood. Respiratory signs (eg, tracheitis, conjunctivitis) may be similar to those of other infectio