What does your farrier say about his hooves and the abscess situation?  Is he normally kept shod?  If he's barefoot then maybe it's not working out for him and he needs some protection - if not shoes then a hoof boot such as easiboot.  I used to give my old laminitic pony formula 4 feet from www.equilife.co.uk, but remember if feeding something for the feet then any effect will take at least a year to be noticeable as that's how long it takes a whole new hoof to grow and an oral supplement will have no effect on the hoof he has at the moment, you would need to use a topical product to keep them nourished from the outside such as a good hoof grease e.g. effol.  Nutrition wise try a conditioning feed to help maintain his weight such as Allen and Page calm and condition.