The lungworm Protostrongylus boughtoni (Nematoda, Metastrongyloidea) in gastropod intermediate hosts and the snowshoe hare, Lepus americanus

Abstract

Natural infections of Protostrongylus boughtoni in intermediate and definitive hosts were examined in Boreal Forest habitats of north central Alberta. Vertigo gouldi was the major intermediate host. Prevalence and intensity of P. boughtoni larvae in V. gouldi were similar among habitats, among size classes of V. gouldi, and temporally. Prevalence of P. boughtoni in adult snowshoe hares was 100%; mean intensity varied monthly at relatively low levels. Juvenile snowshoe hares became infected within a month of birth; intensities increased to relatively high within 3 months and then declined, indicating development of an immune response or decreased exposure to infected snails. No evidence was found for transplacental transmission. Relative rates of flow of P. boughtoni were calculated to determine the importance of snail species and habitat types in transmission of the parasite. Vertigo gouldi accounted for nearly all flow from snails to hares, and most of the flow from snails to hares occurred in dry coniferous and mixed wood habitats.