RESUMO
The study presents the results of a two-year research of protozoan infections of cattles from the Northern-Backa district (VoÑvodina, Serbia). The research was conducted on cow-farms and in private cattle-breeding households, with variuos levels of hygenie. The study included 224 specimens (71 calves, 48 hifers and 105 cows). 22.91% of examined heifers and 15.23% of cows were infected with the ciliate Buxtonella sulcata. The presence of coccidiosis was detected in 45.07% of the calves, 14.58% of the heifers and 6.67% of the cows. The clinical signs of diarrhoea were established in all of the specimens which had more than 1,500 cysts of B.sulcata in 1g of faeces. In the examined calves the number of oocysts was less than 1500 in 1g of faeces, so the coccidiosis did not influence the incidence of the diarrhoea. The results show the first diagnostic record of the ciliate B.sulcata of bovines in Serbia, and this finding contributes to the existing knowledge about the etiopathogenesis of protozoan disease of cattle in this area.