EN
The purpose of the work was to assess the results of relieving cows from bovine enzootic leukaemia taking into account some laboratory tests, ie agar gel diffusion test, ELISA and syncytial test. In the Wrocław district immunodiffusion testing was introduced to standard practice in 1982. Up to 1990 only a small number of animals (9-14%) were evaluated for leukaemia and the percentage of positive seroreactions ranged from 27-7%. The process of the spreading of the EBL virus at that time was significant and was confirmed by positive results of the virus isolation from the peripheral blood of cows and calves coming from herds being treated for enzootic leukaemia. In 1991-1995 mass serological examinations involved the majority of cattle and the percentage of positive results declined to 5.8% in 1991 and 1.67% in 1995. In light of the findings the best results were obtained when the serological tests were introduced as obligatory ones and the cost of the studies were covered by Ministry of Agriculture.