I have a 16 yr old gelding quarter horse and he's an easy keeper. He foundered (in all 4 feet) almost 2 years ago. He lost a bunch of weight and is doing good. His feet are good but the arthritis in his knee is getting worse. If he stands too long his knee gets stiff and he limps around for a while and eventually he starts walking fine. He's not a performance horse and I don't ride him much. I struggle to find time to exercise him, but I'm working on that. To help his joints I'm wanting to give him a powdered supplement, but they tell you to mix it with grain. Since he foundered I haven't fed him any grain. So my question is does anybody know of a grain that I could feed a horse that is prone to gaining weight or foundering?