Parelaphostrongylus andersoni (Nematoda: Protostrongylidae) in caribou (Rangifer tarandus) of northern and central Canada

Abstract

Woodland (Rangifer tarandus caribou) and barren ground (R. t. groenlandicum) caribou are reported for the first time as hosts of Parelaphostrongylus andersoni, greatly extending the known geographic range of this muscle nematode. Up to 56% of caribou in the Beverly herd, central Northwest Territories, passed dorsal-spined first-stage larvae in their feces. Animals less than 3 years old were more frequently infected and passed greater numbers of larvae than older animals. Larval output in winter and spring did not differ. Adults of the four elaphostrongyline nematodes known to occur in caribou are distinguished by their location in the host, the size of the worms, and the size and morphology of the male copulatory structures. There is an urgent need for tested and improved methods of differentiating larvae of P. andersoni and other elaphostrongyline nematodes from those of P. tenuis that cause neurologic disease in various North American cervids. Demonstration of the occurrence of P. andersoni in Rangifer sp. in North America raises the possibility that it originated in Eurasian cervids and may still occur in the Old World.

Serum Biochemistry, Serology, and Parasitology of Boreal Caribou (Rangifer Tarandus Caribou ) in the Northwest Territories, Canada

“…Larvae of Parelaphostrongylus odocoilei, a muscle worm, have been identified in this population of boreal caribou (Jenkins et al, 2005). In addition, P. odocoilei has been isolated from boreal caribou in several locations in Alberta, and P. andersoni has been found in barrenground caribou in the Northwest Territories and in caribou in Labrador, suggesting that these parasites are widespread in woodland caribou of central and northcentral Canada (Gray and Samuel, 1986;Lankester and Hauta, 1989;Jenkins et al, 2005;Kutz et al, 2007). Although P. odocoilei is most likely responsible for the protostrongylid larvae seen in these caribou, concurrent or mixed infection cannot be ruled out without further molecular diagnostics.…”

Prevalence of Echinococcus granulosus and Taenia hydatigena in caribou in north-central Canada

“…Whereas the prevalence of E. granulosus and T. hydatigena tended to increase with age, the prevalence of Parelaphostrongylus andersoni in caribou of the Beverly herd declined progressively with age (Lankester & Hauta, 1989). Also, T. hydatigena was more prevalent in yearling white-tailed deer (Odocoileus virginianus) compared with fawns and deer >2 years old, although intensity tended to increase with age (Addison et ai, 1988).…”

Muscleworms, Parelaphostrongylus Andersoni (Nematoda: Protostrongylidae), Discovered in Columbia White-Tailed Deer From Oregon and Washington: Implications for Biogeography and Host Associations

“…Based on geographically dispersed records for this parasite in O. virginianus across North America, occurrence of P. andersoni in the Pacific Northwest certainly is not completely unexpected (e.g., Mortenson et al, 2006). Limited records for this parasite may reflect inadequate or incomplete sampling , difficulty in demonstrating the presence of adult parasites during necropsy (Lankester and Hauta, 1989), inability to reliably differentiate DSLs of congeners and other protostrongylids in fecal samples (e.g., Jenkins et al, 2005), or an actual disjunct or heterogenous geographic range driven by historical and environmental factors.…”

“…Alternatively, a limited distribution may result from competitive interactions with P. tenuis in zones of contact for these elaphostrongylines in North America (Lankester and Hauta, 1989;). The absence of P. andersoni in deer from some eastern localities suggests this elaphostrongyline may be effectively replaced by P. tenuis on a cline extending northward in eastern North America, but the western limit for the latter has not been clearly documented outside of southern Canada .…”

“…The absence of P. andersoni in deer from some eastern localities suggests this elaphostrongyline may be effectively replaced by P. tenuis on a cline extending northward in eastern North America, but the western limit for the latter has not been clearly documented outside of southern Canada . It has been postulated that the presence of P. tenuis, which is not known to occur in the southeastern United States, suppresses or eliminates infections of P. andersoni by cross-immunity or another mechanism (Lankester and Hauta, 1989;. Interestingly, the few records documenting natural mixed infections in O. virginianus are from the mid-to south Atlantic region of coastal North America.…”