Dogs training collars are extremely controversial training tools.
Most professional trainers prefer positive reinforcement methods rather than administering punishment.
The American Veterinary Society of Animal Behavior suggests focusing on positive reinforcement, and only using punishment methods like shock collars as as a last line of defense, after all other options have been attempted.
The research on the negative affects of shock collars and punishment-based training is also mixed. One UK-based study found that dogs who were trained with shock collars exhibited more behaviors commonly associated with stress and and tension (like excessive yawning).
On the other hand, another study found that shock collars were no more or less effective than a training regiment composed solely of positive reinforcement (treats and praise rewarded for desired behavior).
Dogs trained with shock collars didn't seem to display any higher levels of stress than dogs trained with positive reinforcement. Nor were shock collar trainers more successful than the positive reinforcement camp - basically, it all seemed to be a wash!
However, there is an added element that can effect the outcome and effectiveness of shock collar training - the owner.
The study actually found that some owners were more hesitant and unsure of themselves when using the electric dog collars (76% felt comfortable administering the shock collar training on their own, as opposed to 95% - 100% of owners using positive reinforcement training) - and this did affect dogs in some regard, as dogs exhibited lower tails and more sudden movements away from trainers.
The interesting thing is that these behavioral changes happened even with a group of dog study subjects who wore shock collars with the shocking device off. This implies that it's the owner's lack of confidence and hesitation affecting the dogs, rather than the shock collar itself.
