The investigation of bovine viral diarrhoea virus (BVDV) in bovine abortions in Erzurum, Turkey was undertaken with immunofluorescence, immunohistochemistry and histopathological methods. For this purpose, tissue sections from 56 aborted foetuses were examined. At the end of the study, histopathological lesions were observed in 17(30.36%) samples. Hyperaemia in sinusoids and central veins, degeneration and necrosis of some hepatocytes and cellular infiltration in portal areas were main histopathological changes in liver. In brain sections, hyperaemia, degeneration and necrosis of neurons, spongiosis and vasculitis, especially in BVDV positive sections, were prominent. In addition, there was interstitial or catarrhal pneumonia in lung sections. Positive immunofluorescence staining was detected in 8(14.28%) foetal tissues by direct immunofluorescence method. In immunohistochemical staining, 6(10.71%) samples were found positive. Antigenic localisations were observed in the cytoplasm of neuronal cells, neuroglia and leptomeninges in brain; hepatocytes cytoplasm of the liver; apical portion of bronchiolar epithelium and alveolar macrophages of lung sections. It is concluded that BVDV is an effective factor for the cattle abortion in Erzurum, Turkey.

Key words: Bovine abortion, BVDV, Immunofluorescence, Immunohistochemistry