Dogs may need to "run free" but I myself would 1, not be comfortable with my rottie running free - due to the fact he'd probably scare people "Dangerous dog line" as he's so big (he's still a pup @ 2, but a rottie and the stories exceed everything) and 2, some dogs don't respond when you shout them!! and I've seen that as well - - As I said my dog is always on a lead.... that way if or other animal comes towards him, they do that at THERE owners risk and I would not be footing no vet bill.