The choke chain has come to be regarded as an indispensable aid to training dogs, but even the most time-hallowed practices deserve an occasional critical review. The author has recently completed an investigation into the uses and abuses of choke chains, and failed to find any benefit from using a choker rather than a conventional leather collar. Indeed, there are some very considerable dangers and disadvantages associated with the device. These charges may sound like heresy to many dog-trainers, but to others, it may strike a sympathetic chord.
Mugford, R.A. (1981). Where to put your choker. International Journal for the Study of Animal Problems, 2(5), 249-251.