All Natural Herbs for Breathing Problems in Horses If your horse has breathing problems it can affect their endurance, their speed and cause a sudden decrease in performance. Try Silver Lining Herbs line of specially formulated herbs designed to provide lung and respiratory support in equines. All of our products carry the NASC Quality Seal, which mean we provide only the highest quality herbs and plant formulas for your great equine. Professional riders, world-renowned veterinarians and horse lovers across the U.S. trust Silver Lining Herbs for all their supplemental needs and you will too. Check out these products to promote healthy breathing and respiration in your horse.