EN
The aim of the study was to determine the prevalence and intensity of gastrointestinal parasites in horses from various management systems. The study included 296 horses of different breeds and ages (from 6 months to 20 years), of both sexes, coming from various management systems: group 1 – horses using natural pastures, group 2 – horses pastured on field pastures created by man, group 3 – horses using sand areas. Faeces samples were collected directly from the rectum 1–2 days before worming. Each sample was examined macro- and microscopically (McMaster method). The number of oocysts/eggs per gram of faeces (OPG/EPG) and parasite abundance (average representation of parasites in relation to all animals). The results were subjected to statistical analysis using the Kruskal-Wallis test. Total prevalence of parasites in all groups was 66.89%: E. leucarti 0.68%; Anoplocephalidae 4.73%, P.equorum 9.46% and Strongylidae 64.19%. Total prevalence per group was the following: 1 – 57.43%; 2 – 26.69%; 3 – 6.38%. In all management systems, the dominating parasites belonged to Cyathostominae (group 1 – 77.65%, group 2 – 70.89%, group 3 – 4.25%). The prevalences of P. equorum, Anoplocephalidae, E. leucarti in each group were as follows: group 1 – 10.59; 3.53; 0.59%; group 2 – 11.39; 10.13; 1.27%; group 3 – 2.13; 0; 0%.The average intensities of Strongylildae, P. equorum, Anaplocephalidae and E. leucarti in groups were as follows: group 1 – 606.44; 519.44; 50; 50; group 2 – 472.32; 261.11; 62.5; 50; group 3 – 1150; 450; 0; 0. On the other hand, the average abundances in each group were the following: group 1 – 473.67; 55; 1.76; 0.29; group 2 – 334.81; 29.75; 6.33; 0.63; group 3 – 48.94; 9.57; 0; 0. The statistical analysis did not reveal statistically significant differences between the management system and invasion intensity. However, the analysis, taking into consideration a correlation between the management system and abundance, revealed statistically significant differences. The differences were observed between groups 1 and 3 (pi = 0.0000001) and between groups 2 and 3 (pi = 0.0000001).