Prevalence and seasonal distribution of helminth parasites in red foxes (Vulpes vulpes) from the Zagreb County (Croatia)

An epizootiological survey of leishmaniosis, coccidiosis and parasitic helminths in 67 foxes (Vulpes vulpes) was conducted in Guadalajara (central Spain). Examination for parasitic protozoa revealed prevalences of 74% Leishmania (determined by molecular methods) and 2.9% coccidia oocysts (fecal flotation). Survey of parasitic helminths (fecal flotation/necropsy) demonstrated the presence of nine species, including six nematodes, two cestodes and one trematode. Nematodes were the most common parasites of foxes, followed by cestodes and trematodes. Greater levels of nematodes like Uncinaria, with a free-living stage in its life-cycle, were found in foxes in areas where moist soils were likely to exist, in contrast to areas of semiarid characteristics, where Toxascaris leonina or Trichuris vulpis were predominant. With regard to helminths of importance as human pathogens, trichinoscopy revealed the presence of a relatively high number of foxes (8.9%) infected with Trichinella spiralis. Finally, Toxocara canis infection was less frequent (4.4%) than trichinellosis.

The prevalences of helminth parasites found on red foxes collected in two different habitats of the Ebro Valley, in north-eastern Spain were compared. Twenty helminth species, including one trematode, six cestodes, 12 nematodes and one acanthocephalan were found. Metorchis albidus, Uncinaria stenocephala and Dirofilaria immitis were more prevalent in the irrigated lands close to the main rivers of the study area, whereas Trichuris vulpis and Pterygodermatites affinis showed higher prevalences in the semiarid stepparian habitat. Habitat characteristics need to be considered when surveying helminths over large geographical areas. The study shows that in the Ebro Valley the fox constitutes a reservoir host for several helminth species that are parasites of the domestic dog or the wolf, or may have importance as zoonoses.