Horses kept at grass during winter face welfare risks from cold, mud, and inadequate nutrition that require proactive management to prevent suffering.
Winter horse welfare failures are often failures of preparation and monitoring rather than care. Horses that enter autumn in poor body condition face the winter with insufficient fat reserves to maintain core temperature. Fields that become waterlogged expose horses to mud fever — a painful, chronic bacterial infection of the lower limbs. Grass that has stopped growing provides carbohydrate and protein but limited energy — horses that appear to be grazing adequately may be losing condition without obvious signs. Regular body condition scoring, supplementary forage, appropriate shelter provision, and field management that reduces mud exposure are the foundations of good winter welfare. Rugging decisions made on how cold the owner feels rather than the horse condition score cause unnecessary thermal stress in both directions.