Prevalence and control of benzimidazole-resistant small strongyles on German thoroughbred studs.
The prevalence of benzimidazole-resistant small strongyles was determined in a survey, conducted on 14 thoroughbred studs, which compared the faecal egg counts of groups of horses before and after treatment with the recommended doses of cambendazole (20 mg kg-1 b.w.) or febantel (6 mg kg-1 b.w.). Benzimidazole-resistant cyathostomes were found on all farms examined. Pyrantel pamoate (19 mg kg-1 b.w.), oxibendazole (10 mg kg-1 b.w.) and ivermectin (0.2 mg kg-1 b.w.) reduced the strongyle egg counts on these studs by 97-100% at 2 weeks post-treatment. However, 6 weeks after dosing the reduction of the strongyle egg output had decreased to an average of 67.8% (8.7-97.1%) with pyrantel pamoate and 51.2% (0-95.8%) with oxibendazole, whereas ivermectin still suppressed the egg counts by 98.2% (95-100%).
D000818:Animals; D000871:Anthelmintics / Q000627:therapeutic use*; D001562:Benzimidazoles / Q000494:pharmacology / Q000627:therapeutic use*; D002159:Cambendazole / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D004351:Drug Resistance; D005260:Female; D005860:Germany, West; D006146:Guanidines / Q000627:therapeutic use*; D006736:Horses; D007559:Ivermectin; D007783:Lactones / Q000627:therapeutic use; D008297:Male; D010270:Parasite Egg Count; D011716:Pyrantel Pamoate / Q000627:therapeutic use; D013319:Strongyle Infections, Equine / Q000188:drug therapy* / Q000453:epidemiology / Q000469:parasitology; D013320:Strongyloidea / Q000187:drug effects
D000871:Anthelmintics; D001562:Benzimidazoles; D006146:Guanidines; D007783:Lactones; C011321:oxibendazole; D002159:Cambendazole; D007559:Ivermectin; D011716:Pyrantel Pamoate; C017309:febantel