All Natural Herbs for Horses Lying Down Frequently If your horse is lying down frequently, or for excessive periods, it may be more than sunbathing. It could be fatigue caused by lack of rest, physical exhaustion, or even hoof pain caused by vitamin deficiencies. It could also be your old horse feeling exhausted and needing a rest, and vitamins and supplementation may be the answer. Many professional riders and veterinarians recommend Silver Lining Herbs for old horses and young horses alike. Our all-natural herbal supplements are an NASC Quality Seal holder, and are specially formulated to increase your equine’s energy, improve their hoof health, and help them achieve better health.