The Bloodhound is a large scent-hound, originally bred for hunting deer, wild boar and, since the Middle Ages, for tracking people. In Britain, there have been instances from time to time of the successful use of the Bloodhound to track criminals or missing people. However man-trailing is enjoyed as a sport by British Bloodhound owners, through national working trials, and this enthusiasm has spread to Europe. In addition, while the pure Bloodhound is used to hunt singly, bloodhound packs use bloodhounds crossed with foxhounds to hunt the human scent.