This is an article about children in schools, but every single statement and all the great solutions they come up with for teachers to help kids get off the stress cycle, self-soothe, and get control of themselves 100% applies to dogs as well. When your dog “acts out,” discipline doesn’t help. It perpetuates the toxic stress that then creates more problems later on. This is why I insist so much on teaching dogs Relax on a Mat and other self-soothing behaviors such as default sit or down. Once your dog learns to offer calmer behaviors on his own, your dog is actually moving towards the emotional place to succeed in life and be healthy. If he can’t calm down on his own, gentle, non-confrontational guidance plus more teaching is needed until he can.

http://opinionator.blogs.nytimes.com/2013/11/13/separating-the-child-from-the-trauma/?_r=0