One hundred eighty two equines of different ages, sexes, localities and breeds were examined for EHV-1 infections by clinical examinations, pathological examinations and virus isolation and identification. The EHV-1 was isolated from aborted foeti, nasal swab, vaginal swabs and preputeal swabs on both embryonated chicken eggs and baby hamster kidney (BHK) cell culture. The EHV-1 was identified by serum neutralization test (SNT) using reference antisera specific to EHV-1. The aborted fetuses and their internal organs were grossly and histopathologically examined for the detection of alterations caused by the EHV-1 infection and its inclusion bodies. The results showed that, the clinical signs in EHV-1 infected equines
were fever, respiratory manifestations, abortions, ataxia, and hind limb paralysis and limb edema. The lung of aborted foeti appeared edematous with areas of rubbery texture and the lung tissues showed degenerated bronchiolar epithelium and the alveoli were lined by degenerated epithelial cells. The liver of aborted foeti appeared enlarged, friable, dark and congested. The liver of aborted fetuses showed necrosis of all hepatic tissue and activation of Kupffer cells with hemosiderin. The eosinophilic intranuclear inclusion bodies of EHV-1 were detected in the examined tissues of the aborted foeti. The EHV-1 had pock lesions on the chorio-allantoic membranes of embryonated chicken eggs. Also EHV-1 had the cytopathic
effects in tissue cultures. It was concluded that EHV-1 infections could be diagnosed clinically and confirmed by pathological changes of aborted foeti organs with virus isolation and identification.