Some lamb drenches contain praziquantel, which will kill susceptible adult tapeworms.
But a high and unreported level of praziquantel resistance is now likely in NZ tapeworms; positive tapeworm eggs counts are becoming more common from lamb drench checks. Wormwise advocates using the most effective drench family for other nematodes on the farm, for early season lamb drenches, rather than choosing a product specifically for tapeworm treatment.