[Mucosal disease virus as a cause of enzootic abortion in cattle in Czechoslovakia]

Bovine viral diarrhoea -- mucosal disease (BVD-MD) virus was demonstrated on some farms as the causal agent of enzootic abortions in cattle. On the whole, five non-cytopathogenic strains of the BVD-MD virus were isolated from the organs of aborted foetuses of different age and prematurely born calves. The strains were identified by the direct immunofluorescence method. The same method was also used in detecting the virus antigen in the organs and tissues of colostrum deprived prematurely born calves and also calves born at term. The involvement of the BVD-MD virus in the abortions was demonstrated indirectly by detecting virus-neutralizing antibodies in the serum of heifers and cows, in the pre-colostral sera of newly born calves, and in the body fluids of aborted foetuses. The discussion deals with the importance of the BVD-MD virus as a cause of enzootic abortions, foetal malformations and early postnatal mortality of calves.