Helminth parasitism in the coyote, Canis latrans, from the Rolling Plains of Texas

Abstract

Eighteen helminth species were recovered from 150 coyotes necropsied in West Texas: 2 trematodes, Alaria marcianae (12% of hosts infected) and Alaria sp. (0.6%); 3 cestodes, Taenia pisiformis (39%), T. serialis (4%) and Mesocestoides corti (58%); 2 acanthocephalans, Oncicola canis (26%) and Pachysentis canicola (23%); and 11 nematodes, Physaloptera rara (60%), Pterygondermatites cahirensis (37%), Spirocerca lupi (83%), Subulura s.p. (1.3%), Filaroides osleri (28%), Ancylostoma caninum (87%), Toxascaris leonina (89%), Dermatoxys veligera (1.3%), Syphacia sp. (0.6%), Dirofilaria immitis (0.6%), and Trichuris sp. (0.6%). All hosts were infected with from 1 to 10 helminth species (- x = 5.5 species). Simpson's index was very low (0.12) indicating a diverse helminth fauna. The helminth fauna of West Texas coyotes demonstrated only low similarity with those from other geographic regions in North America. Significant positive relationships were found between pairs of prevalent helminth species in terms of frequency of occurrence. Comparison of mean levels of infection between pairs of helminth species indicated 6 significant relationships. A clumped distribution was indicated in those helminths utilizing arthropod intermediate hosts or paratenic hosts. Analysis of prevalence of helminth species in terms of host sex by frequency of occurrence and mean levels of infection revealed only one significant relationship; T. leonina occurred more frequently in females than males. Similar analysis of age relationships ( ⩽ 1 year and ⩾ 2 years) and helminth parasitism indicated P. rara occurred more frequently in older animals while A. caninum and P. cahirensis occurred more frequently and with higher levels of infection in younger animals. The results of these findings are discussed in terms of food niche and behavioral aspects of this host from the Rolling Plains of Texas.