ABSTRACT
This report deals with the macroscopic, microscopic, pathological and virological diagnosis of field cases of Rift Valley fever in 43 cases of sheep and 3 cases of goats, 4 cases of cattle, 5 cases of buffalos and 4 cases of aborted feti. The examined samples were obtained from Sharqia and Fayoum governorates. The histopathological examination of liver in different cases showed variable degrees of centri- and midzonal eosinophilic necrosis involving almost 2/3 of the lobules and accompanied with intracytoplasmic hyaline inclusion bodies in the hepatocytes. Other lesions included pyknosis, karyorrhexis and depletion of lymphocytes in the spleen and lymph nodes, widespread serosal hemorrhages which were sometimes accompanied by copious blood in the gastrointestinal tract, myocarditis and nephrosis. Strong specific fluorescent reaction was observed in liver, spleen and lymph nodes frozen sections, by application of agar gel precipitation test and dot-ELISA test, liver and spleen of aborted feti, liver and spleen of some cases and the placenta of aborted animals gave positive results