Parasitological survey of Polish primitive horses (Equus caballus gmelini Ant.): influence of age, sex and management strategies on the parasite community

An extensive analysis of the relationship between age, sex, and different types of management strategies relative to the gastrointestinal parasite community of Polish primitive horses was performed on 124 horses maintained in nine farms from four regions of Poland. The horses (96 females and 28 males) were housed in three types of management strategies: stabled (ST), free-ranging (FR) and semi-free (SF). These horses also were divided into three age groups: <3 years, 3 – 10 years and >10 years old. The gastrointestinal parasites were collected following deworming of all horses with anthelmintics containing the macrocyclic lactones and praziquantel. Totally, 66,192 parasite specimens were collected and identified. The analysis of dependence of horse infection with intestinal nematodes using sex, age and management strategies demonstrated that females had significantly heavier infections of strongylids. Young horses (<3 years old) had higher infections of Parascaris equorum and Strongyloides westeri. Free ranging horses were more infected with strongylids, Oxyuris equi and Gasterophilus intestinalis. Thirty-five nematode species, one cestode and one species of the botfly larvae of Gasterophilus were found. Diagnostic deworming examination revealed presence of Parascaris equorum in 27.4 %, Oxyuris equi in 38.7 %, Habronema muscae in 16.9 %, Anoplocephala perfoliata in 42.7 % and Gasterophilus intestinalis in 46.8% in the Polish primitive horses examined. Strongyloides westeri presence was confirmed only by fecal samples examination; threadworms were not observed in these horses after deworming. In the strongylid community, 31 species (6 of subfamily Strongylinae and 25 of Cyathostominae) were found. Significant differences in prevalence of separate strongylid species, or their proportions in the communities were not observed between females and males, or between age groups (p > 0.05). The highest species diversity (n=30 or 31) was observed in the FR horses, the lowest (n=15) – in ST horses. The FR horses had higher prevalence and proportion of large strongyles in the community, in comparison to SF or ST horses (p < 0.05).