The increasing amount of unruly dogs is caused by our humanisation and resulting lack of control of our pet dogs. I see people being dragged to the park all the time, they let the dog go and meet it at the other side.
They don't think their dog chased anything because they didn't see it, meanwhile it's running after ducks. The dog has good recall because it eventually came back.. etc etc.
Unruly = anything from no recall to an dog that bites their handler.
Discuss.