Horses are highly social animals with genuine welfare needs for companionship, and appropriate social management prevents isolation-related suffering.
Keeping horses in isolation is a significant welfare failure regardless of how excellent other management aspects may be. The social deprivation stress of isolation causes chronic anxiety, stereotypic behaviors, and reduced wellbeing. Where multiple horses cannot be kept, cross-species companions provide genuine social value. Management of equine social groupings - minimizing mixing events, maintaining stable groups, providing appropriate companion animals - is a fundamental welfare obligation for all horse keepers.