My hair was on fire by the time I got to this part ( red colour is mine):
"The feed should be low in sugar if the horse has signs of Cushing’s syndrome with altered insulin levels or diabetes.
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Sweet feeds should be avoided. Plain corn (about 25%), barley (about 35%) and oats (about 45%) make a simple, clean mixture without sugar.
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Some horses may not do as well on oats; if that seems to be the case, just use barley and corn. Higher levels of protein, up to 14%, and calories may be needed in the horses with weight loss problems. Laminitis horses that are normal weight or underweight often do well on the senior diets, which are high fat.