Field study of anthelmintic resistance of strongylids in horses
Bauer, C.; Gandras, R.; Stoye, M.; Bürger, H.J.
Berliner und Münchener Tierärztliche Wochenschrift 96(9): 312-316
1983
ISSN/ISBN: 0005-9366 PMID: 6639640 Document Number: 219565
Field trials were conducted on 214 horses in eight premises to evaluate the efficacy of the (pro)benzimidazoles cambendazole, febantel, febantel plus trichlorphon, fenbendazole, mebendazole and tiabendazole as well as pyrantel pamoate against equine strongyles by means of critical egg reduction tests. Pyrantel pamoate which was used on 6 farms reduced the egg output by at least 99%. The efficacy of febantel or its combination with trichlorphon exceeded 98% on only 3 of the 8 farms; on the remaining 5 farms none of the applied benzimidazoles gave satisfactory results. All larvae cultured from faeces after treatment had cyathostomine morphology. The reduced efficiency of benzimidazoles on those five farms was preceded by frequent use of this class of anthelmintics. This is the first report of proven anthelmintic resistance in Germany involving trichoneme strongyles of horses.