The study designs were generally in accordance with the International Cooperation on Harmonisation of Technical Requirements for Registration of Veterinary Medicinal Products-VICH (International harmonisation of anthelmintic efficacy guidelines), “Efficacy of Anthelmintics: General Requirements” GL7 (Vercruysse etal., 2001) and “Efficacy of Anthelmintics: Specific Recommendations for Felines” VICH GL20 (Vercruysse et al.,2002); and the “World Association for the Advancement ofVeterinary Parasitology (WAAVP) guidelines for evaluatingthe efficacy of anthelmintics for dogs and cats” (Jacobs etal., 1994). All cats were purpose-bred for laboratory studiesand were handled with due regard for their welfare and incompliance with Merial Institutional Animal Care and UseCommittee approvals and applicable local regulations