THE PREVALENCE OF BENZIMIDAZOLE-RESISTANT TRICHOSTRONGYLOID NEMATODESIN ANTELOPE COLLECTIONS IN FLORIDA

Although resistance of trichostrongyloid nematodes to benzimidazole an thelmintics is common in domestic ungulates, only one case of benzimid azole resistance (BR) has been documented in captive exotic ungulates. In the present study, an in vitro thiabendazole egg hatch assay was u sed to detect BR in antelope collections in Florida. The purpose of th is study was to measure the prevalence of BR in seven antelope collect ions in Florida and determine if the occurrence of BR was related to t he frequency of anthelmintic usage. Six of the seven collections had e vidence of BR. This study demonstrated that BR is common in antelope i n Florida, and current parasite control practices used in these collec tions, particularly high treatment frequencies, were positively correl ated with the development of BR. Because BR appears to be so prevalent in zoological collections in Florida, the use of these drugs should b e reserved for collections where the efficacy of benzimidazoles has be en confirmed.