Histopathological Study On Ducks Artificially Infected With DEV And The Immunofluorescent Study On The Virus Distribution E On The Paraffine Section

3-month Peking ducks were inoculated subcutaneously with virulent DPV. The hepatocytes showed granular degeneration 4HPI, the nucleus of hepatocytes appeared basophilic conglomerations 6 HPI, necrosis occurred in liver 24HPI. After that,serious congestion, haemorrhage and necrosis foci were observed, acidophilic IIBs were found around the necrosis area 85 HPI. Infitration of lymphocytes occurred in the mucous membrane of esophagus and intestine 6 HPI, mucous glands were damaged after 48 HPI, epithelia of mucous membrane became dissolved and necrotic 85HPI, acidophilic IIBs could be seen in Epithelia. 91 HPI . Lamina propria of duodenum congested and epithelia dissolved 12 HPI, then the epithelia were desquamated 72h HPI, lymphocytes decreased in number 85 HPI, connective tissue of duodenum proliferated 89 HPI. Infiltrated lymphocytes decreased in number 4 HPI, connective tissue of cecum proliferated 12 HPI, then necrosis could be seen in the connective tissue of cecum 72 HPI. Epithelia of mucous membrane of proventriculus dissolved 48 HPI, deep-multiple-gland was filled with fatty droplets and epithelium of proventriculus showed necrosis 85 HPI. Pancreas cells showed granular degeneration before 72 HPI,then dissolution and necrosis. Infiltration of neutrophiles were observed in spleen 6 HPI,the number of lymphocytes of spleen decreased 24 HPI,then congestion,haemorrhage and necrosis with proliferation of reticuloendothelial fibrin were observed in the spleen 85h.The lymphocytes of the medulla of bursa of Fabricius decreased in number 24 HPI,lymph node showed necrosis and reticulocytes proliferation in which we found acidophilic intranuclear inclusion bodies. The necrotic foci could be seen in thymus 24h,then the area of necrotic foci became larger 85 HPI.The blood vessels of lung congested 4 HPI,congestion and haemorrhages were observed in the lung with serous fluid exudation 6 HPI, alveolar septum was thicken 24 HPI, alveolar structure was damaged with infiltration of neutrophiles 48 HPI,then necrosis were observed in lung 85 HPI. Nucleus of neurocytes of cerebrum was enlarged and eccentrically placed 6 HPI, neuronophagia were observed in cerebrum 48 HPI, the number of microglial cells of cerebrum increased 91 HPI.Granular degeneration occured in epithelia of renal tubule 6 HPI, renal globules were damaged 12 HPI, pyknosis of epithelia of renal tubule and coloration of nucleus thickened 24 HPI,then heavy haemorrhages were observed in kidney 85 HPI.Distribution of DPV in vivo was studied in paraffine-embedded sequential tissues by IFA using IgG from rabbit inoculated with purified DPV. The virus were observed primarily in the spleen,thymus and bursa of Fabricius 4 HPI,then DEV spread to the liver,esophagus,intestine and lung.