So it's that time again, and i need to worm, but i have no idea what's safe for a horse with possible digestive issues, maybe ulcers also. What brands are best? What ingredients should i stear clear of? Also, he's currently on Yea Sac, but i'm thinking of giving him a dose of Rebound after worming? Since Yea Sac is a yeast, not a probiotic, is this a good idea, or will be overdoing it? And one last question, has anyone used herbal/natural wormers, and how did you find them?