This study was prompted by the scarcity of information on helminths in Sceloporus lizards of Utah. It reports these worms and includes references to parasites of reptiles in the appendix. A microscopic examination of the coelom, mesenteries, liver, lungs, esophagus, stomach, and intestines of 55 lizards was made, but helminths were recovered only from stomachs and intestines. Examination of S. graciosus yielded Opchoristica scelopori, a cestode found in the duodenum, and Cyrtosomum penneri, C. readi, and C. heynemani, three nematodes of the cecum. The latter two are new nematodes for this host species. Examination of S. undulatus yielded three new nematodes for this host. Skrjabinoptera phrynosoma from the stomach, Physaloptera retusa and Pharyngodon giganticus from the cecum. Examination of S. occidentalis yielded O. scelopori from the duodenum, P. retusa from the stomach, and P. giganticus in the cecum. Examination of S. magister yielded S. phrynosoma and Thubunaea iguanae from the stomach, and from the cecum P. giganticus, C. penneri, and C. readi. New nematodes of S. magister reported in this study are S. phrynosoma, P. retusa, and C. readi.

A survey of helminth parasites of sheep and cattle was conducted to determine the incidence and distribution of these parasites that could be detected by post-mortem examination. Animals were obtained from local abattoirs within the valley, and the viscera were examined for the presence of helminth parasites. Parasites identifies from sheep in order of highest incidence were: Haemonchus contorus, Ostertagia cicumcinta, Chabertia ovina, Nematodirus spathiger, Trichostongylus colubriformis, Thysanosoma actinioides, Trichuris ovis, N. filicollis, Echinococcus granulosus, Strongyloides papillosus, O. ostertagi, Cooperia oncophora, Cysticercus tenuicollis, Fasciola hepatica, Oesophagostomum venulosum, Moniezia expansa, and M. benedieni. Those recovered from cattle in order of highest incidence were: Cooperia oncophora, Ostertagia ostertagi, Fasciola hepatica, C. mcmasteri, O. circumcinta, Moniezia benedeni, Seteria cervi, M. expansa, Chabertia ovina, Haemonchus placei, and Nematodirus spathiger. Many of the parasites encountered require a moist environment for development and survival of the free-living stages. Utah Valley is situated in a semi-arid environment and the additional moisture needed to produce optimal condidtions for larval development, survival, and subsequent transmission is added through irrigation.