Hi Lauren

There is doc on ULCERS in the files section that may have ideas you've not considered.

Nancy C in NH
ECIR Moderator 2003
FACT: Some mares are refractory to good control of IR by the usual diet measures.  See  E. M. Kellon, VMD, Mineral Nutrition and Insulin Resistance, 2013 NO Laminitis! Proceedings, Equine Cushing's and Insulin Resistance Group Inc.