EN
The results of autopsy finding, histopathological and virological examinations of 44 spontaneously aborted fetuses of breed mares are described. In cultures of rabbit kidney cells (RK-13) from the specimens of the spleen, liver and lungs of 18 fetuses Equine arteritis virus (EAV) was isolated. In 11 cases subictericus cases, transudation in body cavities, haemorrhages in serous membranes and haemostasis in mesenteric vessels was observed. Histopathological examinations of the fetuses revealed atrophy of lymphatic tissue in the spleen and mesenterial lymph nodes. Changes characteristic of EVA were seen in arterioles of muscular type of 6 fetuses but they were poorly pronounced. Some cells of tunica adventitia were congested and hyaline changes and disintegratio of mediacites of tunica intima was also visible. Small inflammatory infiltrations in the arterioles were observed only in two examined fetuses.