EFficacy of albendazole for treatment of naturally acquired fasciola hepatica in calves.

In calves given various doses of albendazole as a 4.55% (w/v) drench suspension, removal efficacies against mature Fasciola hepatica were 77.5% with the dose of 7.5 mg/kg; 92.3%, with 10 mg/kg; and 85.9%, with 15 mg/kg. Against immature F hepatica, drug efficacies with these doses were 32.7%, 20.0%, and 36.7%, respectively. Reductions in length and width measurements of mature and immature flukes recovered from the bile ducts correlated with the larger doses reflected a greater efficacy against mature flukes or a possible inhibiting effect of the drug on fluke size or growth. Numbers of eggs recovered in bile at necropsy were reduced by 87.8% with the dose of 7.5 mg/kg; 91.8%, with 10 mg/kg; and 95.6%, with 15 mg/kg.