This study was conducted during an explosive outbreak of infectious laryngotracheitis (ILT) in layers flocks of Hyline breed with a total number 120.000 housed in cages system in Bal'a, East of Tulkarem and North Palestine.
The clinical findings of the disease were gasping, coughing, gurgling, marked dyspnea and expectoration of vigorously in an blood stained mucous obstructing the trachea or larynx.
Some layers showed existence of dried blood around the nostrils and lower beaks, closed eye or eyes, lacrimation and the egg production was decreased 30 %.
The morbidity rate was high, mortality rate reached 12 %.
The necropsy findings of dead birds showed mucoied tracheitis, laryngitis, severe hemorrhages in the trachea and the lumens were filled with mucus mixed with blood, exudates, caseous materials and existence of blood casts along the entire length of the larynx and trachea.
The disease was diagnosed by isolation of the causative agent from the dead and sick birds trachea suspension onto the chorioallantoic membrane (CAM) of 10-12 day- old embryonated chicken eggs and identified by neutralization test using reference antiserum, This study reports the application of PCR in detection of ILTV Thymidine kinase gene (TK gene) using Larynx and tracheal specimen from infected birds
