Lameness will likely be a problem for all horse owners at some point. It is a sign that a horse has an injury that causes pain when it moves or places weight on the affected leg. If the cause of lameness is apparent, you may be able to administer first aid. If not, confine the horse to prevent further damage to the leg and call the veterinarian if mild lameness persists. Horses with severe lameness need prompt veterinary attention, as they are usually experiencing significant pain.