Efficacy of anthelmintic drugs to control Fasciola hepatica in dairy cattle in Peru

Background: Decreasing antiparasitic efficacy of triclabendazole for controlling Fasciola hepatica in dairy cows in the Cajamarca Valley (Peru) has been reported. Objective: To determine the efficacy of four anthelmintic agents across a broader area of Cajamarca province. Methods: Four livestock farms were selected from three provinces in the Cajamarca region. Within each farm, 60 female cattle naturally infected with F. hepatica were chosen. Each farm was divided into four homogeneous groups based on individual animals and parasite burden. The groups were: triclabendazole (12 mg/kg of BW, VO), clorsulon/ivermectin (2 mg/kg and 0.2 mg/kg of BW, SC, respectively), closantel (10 mg/kg of BW, VO), and nitroxynil (10 mg/kg of BW, SC). Efficacy was determined following WAAVP guidelines by measuring the reduction in trematode egg shedding on day 30 post-dosing. Results: Triclabendazole demonstrated insufficient activity through FERCT and CPCR assessments across all four farms. The clorsulon/ivermectin and closantel groups exhibited high efficacy in all farms, while nitroxynil showed varying efficacy results in both types of analysis. Conclusions: Triclabendazole exhibited insufficient activity against F. hepatica. Clorsulon/ivermectin, closantel, and nitroxynil are viable alternatives with promising outcomes for controlling this trematode in the evaluated provinces.