The Shocking Truth About Shock Collars
Shock collars are a punishment based training method that inflicts pain to the dog in order to stop an unwanted behavior, and the shock (pain) stops when the dog offers a behavior that is wanted. Huh? Its kind of like beating your spouse if the dishes are dirty and you want a clean mug for your coffee... I bet you'd quickly find clean dishes all the time, but is that the relationship you are seeking with your beloved canine companion?
Science based training (learning theory) has shown us that dominance training or training that uses aversion techniques creates the release of high levels of cortisol in the brain, and behavioral signs of stress in the dog - even when the electric shock collar is not being used.
Here are a few excellent articles on the results of scientific studies of dogs who were trained using shock collars - these two studies looked at both body posture and stress signals in behavior in the dog when the collars were not in use, as well as general cortisol levels in dogs once electric shock collars were being used on the dogs. https://positivepolicedogs.wordpress.com/2010/10/20/electric-collars-no-thanks/
And please read this article about the cortisol levels found in dogs being trained with shock collars: