Most aggression is based in fear, not dominance. There is a very good chance you either have a dog who is fearful of something and you must try to figure out what. There are tons of good books out there and it's best to find a good trainer to work with. Loki is reactive to big dogs and loud noises - he will start freak out barking. Once you identify the problem there are lots of things you can do to work with your dog.
The other possibility is an unseen medical issue. Loki would snap at us out of the blue when we would reach to pick him up, but he wasn't anti social as he would happily come and lie near us. We worked with him through behavioral methods like giving treats when we picked him up, or asking him to stand up first, which worked OK but we found out the underlying cause was a medical condition (diabetes insipidus) which was causing him pain as his bladder was constantly full. Would you want someone grabbing you around the waist with a full bladder? Now that he is on medication he is fine.
