Liver fluke needs the mud snail to continue the cycle. The eggs in the sheep faeces ( or ay infected animal) use the snail as a host then the snail lays eggs which in turn any grazing animal can eat. Most sheep/cattle farmers use Fasinex as it treats the three stages of fluke. I dont know if there is anything on the market for pigs, but you could phone a company like Merial or Norvatis.If you live in a wetter area and there have been lots of mud snails in the spring/early summer, you can bet that cases of fluke will be very high come autumn.Hope that helps....probably doesn't, but thought I would share!!