Gopal, R M Resistance of field isolates of Trichostrongylus colubriformis and Ostertagia circumcincta to ivermectin. [electronic resource] - International journal for parasitology May 1999 - 781-6 p. digital Publication Type: Comparative Study; Journal Article ISSN: 0020-7519 Standard No.: 10.1016/s0020-7519(99)00032-6 doi Subjects--Topical Terms: Administration, OralAnimalsAnthelmintics--pharmacologyDrug ResistanceFeces--parasitologyGoat Diseases--drug therapyGoats--parasitologyIvermectin--analogs & derivativesLethal Dose 50Ostertagia--drug effectsOstertagiasis--drug therapyParasite Egg Count--methodsSheep--parasitologySheep Diseases--drug therapyTime FactorsTrichostrongylosis--drug therapyTrichostrongylus--drug effects