Quote:
Originally Posted by fostermom  Dogs do what is rewarding for them...PERIOD |
This quote from your trainer sums it up...yep, they do what is rewarding for them...PERIOD. For this particular dog the jumping/bouncing/grabbing behavior was rewarding for him, and so he kept doing it (the behavior was self-reinforcing) until you effectively broke his focus with your voice.
Sometimes it is necessary to take the "fun" out of behaviors that dogs find rewarding, but that are in appropriate in our human world (for example: we work on recalls with a whole lot of rescue dogs that started life untrained and need to learn that it's just not "fun" to do one's own thing). There are many ways to do that, it sounds like your raised voice worked well in this situation. Of course in the ideal situation where you start with a puppy it's not always necessary (especially if you do a good job of convincing said puppy that YOU are the best thing in his/her life), but it's much different when working with an unruly adult dog (with little to no training and/or socialization to start with).