Horses are highly social animals that evolved in herds. Isolation — keeping horses singly without conspecific contact — is one of the most common and serious welfare failures in horse management.
Social isolation is a profound welfare failure for horses. They are highly social animals that have evolved not just to tolerate but to require conspecific companionship. Isolated horses show chronic stress responses — elevated cortisol, cardiovascular arousal, and the development of stereotypic oral behaviours that, once established, persist even when social contact is restored. Individual ownership of single horses, without arrangement for social contact, causes welfare compromise that many owners do not recognise as a problem.