Yvette Nout-Lomas, DVM, PhD, of Colorado State University, explains that underweight horses cannot perform at their maximum level and are at risk of developing gastric and metabolic issues. Evaluating the horse’s source of roughage, increasing his concentrate feed, and adding fat sources can help pack on the pounds. Because it’s important to avoid feeding too much concentrate at once, adding other sources of fat can help. Talk to your veterinarian about weight-gain goals to find a way to safely increase your horse’s intake without causing additional concerns.