[Enzootic bovine leukaemia, diagnosis, distribution and control in the Netherlands (author's transl)]

The results of studies on the incidence of enzootic bovine leukaemia in the Netherlands from 1968 to 1975 inclusive are given. The serological methods used (fluorescent antibody technique, immunoperoxidase test, micro complement fixation test and gel diffusion test) were found to be of great value especially for the early diagnosis of the disease. Antibodies to bovine leukaemia virus are already detected long before the onset of persistent lymphocytosis. The results obtained so far with serological methods confirm earlier haematological findings that enzootic bovine leukaemia is non-existent in the Dutch Friesian-Holstein and Meuse-Rhine-IJssel breeds. The first cases of enzootic bovine leukaemia were observed in import cattle in 1970. The geographic distribution of farms exploiting import cattle in which the disease has been diagnosed is presented on chart 1. Methods used to control enzootic bovine leukaemia are briefly described.