My vets have not had me worry so much about pulling food, but it is important to try to avoid giving it too closely with any other medication, as it could cause the other medication to be less effective.
When I first started using it, horse had already been on Gastrogard for over a month. I’d say within a week of adding Sucralfate 2x a day (with the Gastrogard dose given in the middle of the day), he started to get a lot less spooky, which to me was a sign he was feeling better. I was finally able to wean off the Gastrogard. The vet recommended giving that dose for a month or two then trying to reduce to 1x a day for another month before taking him off. Because he responds so well to it, I will also give it as kind of a one-off as well if he doesn’t have any other reason to be on it, where you’d normally give Ulcergard as a preventative.
All that said, I had tried it for another horse with no noticeable change at all.