They were used as a pack dog to hunt large game such as red deer, wild boar and roe deer or smaller animals such as fox. "Grand" does not necessarily refer to size, "in most cases it is simply a label for a pack that is used for larger game".
These dogs were employed in packs to hunt bigger prey like red deer, wild boar, and roe deer, as well as smaller animals such as fox. The label "grand" usually signifies a pack that targets larger game.