Some studies on viruses affecting ducks with the characterization of the isolates

tow virus isolates causing mortality among young ducklings were obtained during outbreaks in two farms in Cairo. the epidemiological history of both outbreaks J the clinicalmanifestaions, post mortem findin~s as well as histopatho- lOGical examination were simulatin that described for duck hepatitis. 1, The serial proparu3tion of the two isolates in embryonated chicken e~gs indicated that ir:cegular mortality pattern of the