Studies on the incidence and pathology of naturally occurring duck plague in Assam

Outbreak of Duck plague in the state of Assam during the period from Augest’2003 to June ’2005 has been reported. The incidence was recorded as 21.7 per cent. The clinical signs recorded were greenish watery diarrhea, mucous discharge from mouth, droopiness, soiled vent, inappetence and deposition of caseous materials in the eyelid. Grossly, characteristic “paint brush” appearance of the heart was observed in few cases due to severe petechiae over the epicardium. The longitudinal folds of the esophagus showed the presence of thick- white patchy diphtheritic membrane mostly in the adult birds. Microscopically, the prominent tissue changes were congestion and haemorrhage of the parenchymatous organs. Liver showed varying degree of degeneration to multiple areas of focal coagulative necrosis with disruption of the hepatic cords. Characteristic intranuclear eosinophilic inclusion bodies were noticed in the degenerated hepatocytes with clear halos.