Certain diet restrictions may be necessary for horses that are insulin-resistant as well as horses with laminitis, EMS, PPID, and other maladies. These horses will probably need to ingest low-carb nutrients. Exercise is also highly recommended. It is very important that these horses keep an optimum weight and are not allowed to become obese.
Professor Geor of Michigan State suggests feeding a high-forage diet with little to no grain added. Forage should consist of low-grade hay. Vitamins and minerals that are missed from such a low-calorie diet can be given to balance out the horse’s individual requirements. Special attention should be paid to the horse’s intake of vitamin E, copper, and zinc.
Pasture-grazing should be very closely monitored or possibly not done at all. Pasture grass can sometimes put weight on a horse very quickly.
It is not a good idea to starve the horse when reducing its intake. Any feed changes should be done very gradually and carefully. Meals should be given in three to four small rations per day. A dieting horse may be tempted to eat its bedding; therefore, it is best to try to use something other than shavings, straw, or other materials a horse might eat.