Results of a survey of the parasites of the collared peccary (Dicotyles tajacu angulatus) in Texas are presented. Three ectoparasites, Amblyomma cajennense, Dermacentor variabilis, and Pulex porcinus were very common on peccaries from south Texas, but less common or absent in arid west Texas. Sucking lice, Pecaroecus javalii, were common on peccaries from west Texas, but were not found in south Texas. The known range of this louse in Texas is extended into the Big Bend area. Two ticks, Amblyomma inornatum and Haemaphysalis leporis-palustris, were found infrequently.

Five of nine species of endoparasites found in this survey (Dirofilaria acutiuscula, Parabronema pecariae, Parostertagia heterospiculum, Physocephalus sp., and Texicospirura turki) were prevalent. Three species, D. acutiuscula, Gongylonema baylisi, and Fascioloides magna, are reported from North American peccaries for the first time. The geographic distribution of the large American liver fluke, F. magna, coincided with an area where the parasite is enzootic in white-tailed deer.

It is concluded that parasitism was of little importance in population control of peccaries during the period of the study.