Helminths of Big Game Mammals in South Dakota

Abstract

A study was undertaken to determine the incidence, distribution, and relative importance of helminths in wild ruminants of South Dakota. Big game species examined and numbers of helminth species found were as follows: 83 white-tailed deer (5 species of nematodes, 3 of cestodes), 30 mule deer (3 spp. of nematodes, 3 of cestodes), 60 pronghorn antelope (13 spp. of nematodes, 2 of cestodes), 20 elk (5 spp. of nematodes, 2 of cestodes), 5 bison (7 spp. of nematodes, 1 of cestode), 3 bighorn sheep (6 spp. of nematodes, 2 of cestodes), and one mountain goat (3 spp. of nematodes). There were new host records for several species of nematodes. The absence of trematodes was conspicuous. The pronghorn antelope was the most heavily parasitized of the 7 species sampled. Since they occur on livestock rangelands in the western part of the state, they may have some importance as reservoirs for helminths of sheep and cattle. The presence of lungworms, Protostrongylus spp., in the bighorn sheep and mountain goat merits further investigation, as lungworms have been implicated as limiting factors in populations elsewhere. Seven species of big game mammals occur in South Dakota, viz., mule deer, white-tailed deer, pronghorn antelope, elk, mountain goat, bighorn sheep, and bison. All except bighorn sheep are hunted, either in regular hunting seasons or in strictly controlled, limited hunts and herd thinning operations. Aside from the importance of these animals to sportsmen, many of them occur on rangelands utilized by domestic livestock and are of importance to stockmen. There has been no previous statewide study on the parasites of these game mammals. This study was undertaken to determine the incidence, distribution, and relative importance of helminths in wild ruminants of the state. The sources of the game animals are shown in Figure 1. A companion study involved a sampling of many of these same animals for pesticide residues, the results of which have been reported elsewhere (Greenwood et al., 1967; Moore et al., 1968).