I noticed over the fall/winter, my senior horse was having on and off again diarrhea. He had a lot going on last spring/summer, a vaccine complication that required heavy-duty antibiotics, moved from North Carolina to Idaho, change in diet due to change in geography, and he's an oldie! On my farrier's suggestion, I added beer and brewers yeast to his diet, and he hasn't had an episode of diarrhea since! (It's been like 4 months!) Going to have my vet out soon and will discuss it with him as well. Here's what I do! ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-o7Nbbsovdd8.html