I have a 26 year old horse that had consistent bad diarrhea all fall and winter. I switched him from a very rich hay to a grass hay with no alfalfa and it helped a little but didn't make much of a difference. I tried switching him to different feeds including bran which the vet had recommended. The vet did a fecal which was negative. He continued to have bad diarrhea. It was so bad that even after giving him treats he would have a little bit a few minutes later. I really thought I would have to put him down this year but about the beginning of this month his diarrhea completely cleared up. It's the strangest thing. He had diarrhea last winter as well but it was not nearly as bad as it was this winter. Does anyone have any ideas about what could be going on? The only thing I can think of is that he's getting a little bit of grass now that we're in spring but there's really not much grass in the paddock so I don't think that would be enough to really change things. Nothing else has changed, he's been in the same paddock this whole time. I'm afraid his diarrhea is going to start up again this winter.