Cattle can also get it. The best preventative is a trio of Muscovy ducks. They will eat the snails that carry meningeal worm and liver flukes as well. Muscovies will set and brood their own young and are, from what I can gather, quite tasty. The lady we got our sheep from has cattle, sheep, goats, muscovies and Great Pyrenees to watch over them all. She has trained her muscovies to come up every night to the barn, where she gives them corn and closes them up for the night and lets them out in the mornings. Certain sections of her fence is a cow panel, which the ducks can scramble through the large holes to access her pastures and lake.