The words 'dominance' and 'alpha' have fallen out of favour with regard to behaviour, due to being misinterpreted by owners to mean that your pet is always trying to 'get one over you'.
Due to the fall from grace of verbage, there is now even more confusion about behaviour.
Dogs still have the minds of wolves, they still see you as their pack or family. They intuatively know that someone must be the pack leader if the pack is to survive, and if your communication tactics do not elicit this then they will feel that they have to take on this role.
The problem with this is that due to the way we keep our pets, we do not allow them to 'grow up' mentally, they are not allowed to learn to hunt or defend and therefore most of them are absolutely terrified of taking up this position, and haven't got a clue how to do it. This is when we tend to see behaviour issues as the dog takes on a role he/she has no idea how to do, gets very stressed performing it, but uses whatever previous knowledge they have at their disposal to attempt to cope.
Remember that out in the wild the pack leadership is always changing, so they need consistancy in communication letting them know that they need not take on such a stressful role, you have it covered.
There are many ways to achieve this, and we can teach you via one to one consultations. If you feel you could do with some pointers, please get in touch. http://caninehealth101.web.officelive.com/