Anthelmintic resistance of Haemonchus contortus from sheep flocks in Brazil: concordance of in vivo and in vitro (RESISTA-Test©) methods

Abstract This study evaluated the resistance status of Haemonchus contortus from sheep flocks in state São Paulo, Brazil, through comparison between fecal egg count reduction test (FECRT) and larval development (LDT). For FECRT, 35 were selected each five divided into groups treated with: benzimidazole, levamisole, ivermectin, monepantel control. Feces collected for EPG cultures. The LDT was performed using thiabendazole (TBZ), levamisole (LEV), ivermectin aglycone (IVM-A) Zolvix (ZLV). Resistance to all drugs detected FECRT 100% flocks, except relation ZLV (40% resistant 20% suspected resistance). indicated TBZ IVM-A LEV 80% 10%. Total agreement obtained two tests IVM (k = 1.0), while 0.8) 0.9), substantial almost perfect obtained, respectively. concordance significant, thus showing that it is possible use outcome predict hence validating former as a fast diagnostic by farmers Brazil.