ABSTRACT
A private farm at Giza govemorate of three hundred sheep was subjected for virological, immuno florescent, immuno cytochemical and histopathological examinations. In this farm three sheep were dead [1% mortality] and forty animals [13% morbidity] showed diarrhea, fever [3 9°C to 40°C] and muco to muco- purulent nasal discharges associated with mild cough. This study was triggered by isolation of the causative virus from nasal swabs of sick animals and tissues of dead animals on Madin Darby Bovine Kidney [MDBK] cells. The causative virus was identified as Bovine Virus Diarrhea [BVD] by usingindirect immuno fluorescent antibody technique [IFAT] followed by immuno cytochemical identification by using cell culture irnmuno peroxides test. Dead animals subjected to autopsy and histopathological examination of different organs and lymph nodes. Marked involvement of the lymphoid tissues particularly the mesenteric lymph nodes and peyeres patches of the intestinal ileum were prominent on histopathological examination, in addition to necrosis of the tips of the intestinal villi of the ileum and necrosis of the intestinal gland. This study concluded that infection with BVDV should be considered as one of infectious causes of enteritis