When one of those dogs tries to escape their prison, what happens? They are hunted down and returned to their cell. Best case scenario they find another prison

When one of those dogs tries to escape their prison, what happens? They are hunted down and returned to their cell. Best case scenario they find another prison with nicer guards and they are "allowed" to transfer. If the old prison wants them back, it can forcibly take them. But I guess I see why it has to be that way. There's nowhere on Earth left to go that hasn't been turned into a prison other than the uninhabitable places.