This research was performed to determine the pathogenesis of the Duck Virus Enteritis (DVE) and Salmonella Enteritidisseparately or combined on experimentally infected ducks and evaluating the role of XPC prebiotic in reducing these pathological changes observed on the different organs. The experiment was carried out on 80 Muscovy ducks, equally divided into 8 groups. The group (1) was kept as control. Group (2) was administered 1 ml / L from prebiotic XPC Diamond V in drinking water from the first day of age till the end of the experiment. Group (3) at 12 days of age infected intramuscularly by (1 ml/duck) Duck Virus Enteritis (DVE) homogenates previously prepared. At the same age (12days) group (4) was infected by Salmonella Enteritidis strain orally. Group (5) was infected by both Duck Virus Enteritis homogenate suspension and Salmonella Enteritidis with the same dose and 12 days age. Groups (6,7and8) were administered 1 ml / L from prebiotic XPC in drinking water from the first day of age till the end of the experiment. In the same time groups (6,7and8) infected at 12 day of age by Duck Virus Enteritis organs homogenate suspension, Salmonella Enteritidis and both, respectively with the same dose as groups (3,4 and 5). Tissue samples were collected for viral test and pathological examination when the clinical symptom of the disease appeared. Necropsy was performed and tissue specimen were collected from liver, intestine, esophagus, heart, kidneys, spleen and bursa of Fabricius and fixed in 10% buffered neutral formalin solution for histopathological and immunohistochemistry examination.                     
     The histopathological results revealed congestion in all blood vessels of the most infected groups together with recent thrombus in portal vein of Salmonella enteritidis infected group. Degeneration and necrosis with variable degree in addition, inflammatory cells infiltration in different organs of the infected groups were observed. Intranuclear inclusion bodies were seen in the degenerating hepatocytes and in the intestinal epithelium in DVE infected groups. The lesions were alleviated in groups which administered XPC prebiotic and infected with Duck Virus Enteritis or Salmonella Enteritidis and both.
   It could be concluded that XPC prebiotic alleviated the immunological and pathological alteration induced from the experimentally infected ducks by Duck Virus Enteritis or Salmonella  Enteritidis  infection andboth .