I wish I knew! I almost hate that it works. Supposedly it has something to do with how they process the oats.
My horse was recently diagnosed (finally) with an SI injury. He’d been starting to display some of the weird hind gut things my other horse used to do (whom I wrote about on this thread already). I think low back pain and gut pain can each make the other worse. I’d already done a full treatment of omeprazole for other reasons, and one vet suggested Sucralfate 2x a day with the omeprazole dose in between them, trying to taper off omeprazole. Then keep on Sucralfate for at least a month, then try to go down to 1x day. He did great on the 2x a day dose. I should mention horse also gets Platinum GI. Sour smelling poops and the weird behaviors when I tried 1x a day. I use the pills, which dissolve super fast in water. I wasn’t sure he’d eat a flavored powder. But at 12 pills per dose and $150 a bottle of pills, that was adding up at 2x a day. So, I bought some Succeed and started the loading dose while he was still getting Sucralfate 1x a day. I’m still on the 2x a day Succeed but so far so good that I have been able to stop the Sucralfate.
I think I will use Sucralfate for this horse in lieu of omeprazole in the future for short term stressful events, but it’s not enough really once there’s already some kind of imbalance. We have also treated the SI with Pro Stride to hopefully reduce further discomfort and inflammation in that area of the body.