Veterinary Record · 1992 · 290 citations · 0 references
Veterinary MedicineAnimal SciencesVeterinary ParasitologyDiagnostic ParasitologyParasitologyVeterinary Parasitic DiseasesAnthelmintic ResistanceAntiparasitic Drug ResistanceAntiparasitic ResistanceNematode BiologyNematode DetectionNematode DiagnosisAnthelmintic AgentsAnthelmintic Screening AssaysDose ResponseDose-response ScreeningLarval Development AssayLethal Concentration 50Lethal Concentration AssessmentNematode Resistance Screening
A microlarval development test for the detection of anthelmintic resistance in nematodes is described. Haemonchus contortus, Teladorsagia circumcincta and Trichostrongylus colubriformis eggs were cultured to third stage larvae in the presence of Earle's balanced salt solution, yeast extract and bacteria in a total volume of 150 microliters. Good dose-response data were obtained with thiabendazole, levamisole, pyrantel tartrate and ivermectin allowing the determination of the 50 per cent lethal concentration and of resistance factors when resistant strains were available. The test was found to be accurate, sensitive, easy to carry out and applicable to the routine detection of resistance.