The aim of the study was to analyze the distribution of the main groups of parasitic helminths within the small intestine of the red fox on the example of animals coming from eastern Poland. Two hundred and sixteen red foxes shot in eastern Poland were used in the investigation. Before examination, each small intestine was divided into three equal parts: anterior (A), middle (M), and posterior (P). Each part was examined separately with the sedimentation and counting technique. Six different types of intestinal parasites were detected: Alaria alata (78.7%), Mesocestoides spp. (78.2%), hookworms (72.7%), Taenia spp. (53.2%), Toxocara/Toxascaris (43.1%), and Echinococcus multilocularis (18.5%). Alaria alata was most often found in A and in the only-A variant. Taenia spp. and Toxocara/Toxascaris occurred often in A and were the second (after A. alata) parasites in terms of frequency occurring in the only-A variant. Mesocestoides spp. was most commonly located in M. Parasites with predilection sites located mainly in M and P were E. multilocularis and hookworms. In all parasite species, the variant covering the entire intestine (A + M + P) was found in samples with a higher intensity compared to variants limited to one or two fragments. Our investigation, as one of the few of its type, conducted a comprehensive analysis of the distribution of intestinal helminths in the small intestine of the red fox. It showed significant differences in the distribution of parasitic helminths in the small intestine of the red fox. Determining typical predilection sites for parasites in the intestine can be helpful in creating effective diagnostic methods.
Keywords: Alaria; Echinococcus; Mesocestoides; Poland; Taenia; Toxascaris; Toxocara; distribution; helminths; hookworms; intestine; red fox.