Pathological Studies On Swollen Head Syndrome Of Chickens

The present investigations were performed on 9 poultry farms of about 198,000 chickens atDakahliaGovernorate, during the period from September 2002 to September 2003. Isolation and identification of the causative agents were done. Clinically, the affectedconjunctivitis and respiratory signs mainly nasal discharge, sneezing,fever and coughing. Macroscopically, congestion of the trachea and lungs together with tracheitis and pneumonia were seen. Cyanosis of the combs andwattles in addition to the presence of exudate in the nasal passagewere detected. Bacteriological and serological examination revealed isolation of TRT virus ”Swollen head syndrome”, Pasteurella multocida,Infectious coryza and Omithobacterium rhinotracheale (ORT). The predilection seats of these pathogens were the respiratory tract, hearts,liver, spleen, kidney, intestine and brain.Histopathologically, the skin of the head was suffered fromsubcutaneous oedema with leukocytic infiltration. Nasal cavity and sinuses showed sinusitis with leukocytic infiltration and hyperplasia of the nasal glands. Trachea showed tracheitis together wit