An evaluation of the efficacy of compound alpha and triclabendazole against two isolates of Fasciola hepatica

The results showed that, whilst compound alpha was very active against adult TCBZ-susceptible flukes, producing a 100% reduction in faecal egg counts, it only caused a 62.5% reduction in fluke burden against juvenile flukes. Moreover, compound alpha was not effective against any stage of infection with TCBZ-resistant F. hepatica in sheep. Data from the trial also revealed biological differences between the two isolates. Thus, Sligo flukes were smaller in size and produced fewer eggs than the Cullompton flukes and their cysts were less infective to sheep. However, they reached the bile ducts more quickly and their eggs appeared in the faeces >2 weeks earlier.