It is my understanding that they are used as a "step up(?) " in managing a dog from the long familiar "choke chain" as they came to be known. It pains me to imagine the use, much less one being left on a dog as a regular collar. Thank goodness for our earth angels who replace this very painful device with a dignified and beautiful collar a dog deserves. I have seen Prong Collars on the shelves of local Pet Stores in various sizes, not only for use with large breeds.
Ben is blessed to have a new, caring person in his life.