Insulin Resistantance in Animals

I have a Shetland pony, Humphrey, who is Insulin Resistant.   This is rather like being a diabetic in human terms and cannot be 'cured'; only controlled by diet.   Humphrey is also very laminitic prone and I have to constantly monitor his grass intake to prevent him having a laminitic or founder attack. A couple of weeks after first feeding Humphrey flax seed oil he had a new lease of life.