The aim of this diploma thesis was to evaluate the issue of endoparasitosis in horses in breeding in Brno and its surroundings. From November 2015 to January 2017, four stables with different numbers of horses with their different dispositions (age, sex, horse performance) were monitored. In total, 30 horses were observed and 450 samples of equine faeces were collected and analyzed. Samples were analyzed using flotation methods using the Breza solution. It was found that 82 % of the samples were infected with 0-5 eggs of Strongylidae parasites. The work has shown that the number of parasites egg negatively affect the horse health. The resistance of parasites to deworming products was not proven.