Infectious laryngotracheitis (ILT) in broilers is a re-emerging, acute, highly contagious respiratory disease caused by Gallid alphaherpesvirus-1 (GaHV-1), also known as infectious laryngotracheitis virus (ILTV). It affects the conjunctiva, larynx, and trachea, resulting in severe respiratory distress. In its acute, classical form, bloody mucus expectoration is typical. ILT is globally distributed and economically important in broilers, breeders and layers.