Some Studies on Swollen Head Syndrome in Broiler Chickens in Egypt

Abstract

Swollen Head Syndrome (SHS) is a disease of upper respiratory tract affecting broilers and broiler breeders which resulted in inflammatory exudates beneath the skin. SHS has been described as a multi-factorial disease where the initial lesion mainly caused by avian Metapneumo virus (aMPV), while the clinical signs are a consequence of bacterial complications and the severity of the disease depends on environmental factors. This study was planned to detect and try to isolate the etiological agents of SHS from 40 broiler flocks in 3 Egyptian Governorates (Sharkia, Dakahlia and Damietta). The chickens incorporated swollen heads and respiratory manifestations as nasal discharges, coughing, tracheal rales and frothy conjunctivitis from different localities. Samples included trachea and lung tissues, choanal cleft swabs and scraps from sinuses and turbinates. The AMPV subtype B was detected in 5 flocks by Real Time Polymerase Chain Reaction (RRT-PCR) -using 2 specific probes for differentiation of subtypes A and B. the AMPV-subtype B was detected with the percentage of 12.5%. Bacterial examination of collected samples revealed presence of mixed infection in some of examined flocks with isolation of E. coli in a percentage of 70%; Proteus mirabilis 40% and Pseudomonas aeruginosa (25%). In conclusion, to our knowledge, this is the first detection of aMPV among broiler chickens suffering from SHS in Egypt, using RRT-PCR in concurrent bacterial infections with E. coli, P. mirabilis and P. aeruginosa.