I remember a couple years ago I was going to be turning my heifers out to really rich grass with lot's of alfalfa and I called all the feed mills to see if I could give them anything before hand as prevention.It is always better to prevent then to treat after the fact.I think I talked to 7 different feed mills in the area and no one new of anything besides feeding rumensin in a grain ration?So I am assuming that you called your vet clinic and nutritionist also.I don't know why we can't get anything like that anymore.Keep us posted if you find any as this year may be a bad one for bloat with all the rain we have been having.Good Luck I hope you don't lose your clients.