Editor’s Note: This excerpt is from Chapter 3 of Care & Management of Horses by Heather Smith Thomas. 

Some horses present special challenges, such as being too thin, too fat, or sick. Some horses are finicky and are hard to keep weight on, especially when working. The first option is to increase the feed’s energy density by adding grain or fat to the diet. Weight loss in spite of plentiful feed may be a sign the horse is being overconditioned.

Increasing good roughage or adding nutrient-rich legume hay can usually help the thin, idle horse or one doing moderate work. A hard-working horse, however, will not tolerate the extra protein some feeds (such as alfalfa) provide, with heat produced during digestion. A better choice might be rehydrated beet pulp, with its highly digestible fiber, low protein, low vitamin-mineral content (unlikely to upset the diet’s mineral balance), and palatability. Unlike grain, it is safe to feed in relatively large quantities and can be added to a grain ration to give greater digestibility. For horses that just pick at hay, beet pulp often can be a good substitute for part of it.

The hard-working horse cannot eat enough roughage to supply his needs, particularly if he is finicky, tired, or dehydrated. If a horse won’t eat enough hay, he can usually be tempted with something more lush and palatable, such as fresh green grass, or rehydrated beet pulp. A tired, dehydrated horse often will eat green grass when he won’t touch anything else. You can also soak a flake of hay in water