Therapeutic efficacy of triclabendazole in comparison to combination of triclabendazole and levamisole in sheep naturally infected with Fasciola sp.

Fascioliasis is an important parasitic disease which affects productivity of ruminants, and imposes significant economic losses. Benzimidazoles are effective in the treatment of fascioliasis; however, there are several reports on benzimidazoles resistant flukes. Combinational therapy is an approach to delay the emergence of resistant flukes. The present study aimed to compare the efficacy of triclabendazole (TBZ) and combination of triclabendazole and levamisole (TBZ + LVM) in the treatment of sheep naturally infected with Fasciola sp. For this purpose, 40 ewes infected with Fasciola sp. in three groups received TBZ, and TBZ + LVM, or remained untreated as CON. Fecal egg count (FEC), fecal egg count reduction (FECR), liver enzymes activity, albumin, globulin, and total protein levels were measured on day 0, 7, 14, and 28 post treatments. Obtained results showed that treatment with TBZ and TBZ + LVM resulted in significant reduction in FEC (P < 0.05), and FECR reached to values of higher than 90% on 28 day post treatment. The FEC for TBZ + LMV on day 7 and 14 were 12.25 ± 3.82 and 3.08 ± 1.03, respectively which was significantly lower in comparison to TBZ and CON (P < 0.05). Efficacy of TBZ + LMV was higher than TBZ on day 7 and 14 post treatment; however, no significant difference was observed on 28 day. The liver enzyme activities on days 7 and 14 were lower in the TBZ + LVM sheep in comparison to the TBZ and CON. Treatment with TBZ or TBZ + LVM resulted in an increase in albumin and a decrease in globulin. Over all, the present study clarified the importance of combinational therapy, and demonstrated that combination of TBZ + LVM resulted in higher efficacy and earlier improvement of liver conditions in sheep naturally infected with Fasciola sp.