The reason i was looking at more prevention than cure is because it seems they don’t actually have to eat a snail to get it – they can get it from the slime snails leave behind & you can’t really avoid that because it’s everywhere. Cass sometimes nips a piece of long grass and chews it when we are out and there’s no way of knowing what’s been on it.
i think prevention is either regular chemical worming or regular faeces samples to check for the larvae (if you see last link) unless anyone else knows any different?