One hundred & eighty samples collected from commercial layers,
broiler, breeders and native breeds farms to detect the incidence of
infectious coryza in Dakahlia Governorate. 12 isolates of Haemophilus
paragallinarum (HPG) were isolated, these isolates could be identified
morphologically, biochemically and serologically into 8 isolates belonged
to serotype A and the other 4 isolates belonged to serotype C.The
antibiogram sensitivity test prove d that the enrofloxacin was the most
effective antibiotic followed by ampicillin, ciprofloxacin, amoxicillin,
and the lowest one was pencillin.