Prospect Park

8:00 A.M., two joggers behind rink, headed from lullwater to road, preceded by loose dog
8:05 A.M., 1 loose dog preceding its owner along path from nethermead to wellhouse road
8:25 A.M., 1 loose dog romping around lullwater bridge

Note our use of the terms "unleashed" and "loose" dogs. "Off-leash" seems to be a neologistic euphemism; that is the term chosen by the so-called "off-leash community". It seems intended to imply that the dog, while not on the leash, is under the owner's full control and hence there is no reason for the dog to have been leashed in the first place.