Extract from Dr Roger Mugford's book "Dog Training the Mugford way" available on his website at http://www.companyofanimals.co.uk
Canine society is like a cast system. The pack is dominated by one or two individuals, which with a pet dog in the house will be a human. If a dog is allowed to dominate people, he can literally bite the hand that feeds him.
The rules of dominance in dogs are quite clearly defined, so it should be easy to turn the tables and establish authority over a pushy dog as follows:
Keep a height advantage
Never allow the dog on chairs, laps or beds as this brings him up to your level reinforcing social rank. Ideally, exclude from bedrooms and even upstairs.
Don’t be pushed around
If the dog initiates any activity, even friendship, ignore him. Later, YOU command "come", "sit", then stroke the dog when it suits you.
Enforce every command
As you are the boss, you make the rules and must make sure they are obeyed. Otherwise don’t give commands, but remain silent.
Handle the dog
Especially around the head, shoulders and paws.
Games are serious
Don’t let the dog win or even play tug of war, or rough and tumble on top of you. Controlled games such as "sit" (throw) "fetch" are better. Chase games are fine as long as you are the one doing the chasing.
The basic "sit-stay-come-sit" (reward) sequence is easily trained with a head collar and extending lead. If not, join a training class, but remember that you must do the work.
Pulling dogs are in control: make the dog follow, and enforce the "heel’ command. If you have difficulty training "heel", use a head collar rather than a choke chain.
Substitute indulgent "human-type" food with basic rations of a complete, dry dog food e.g. Science Diet. No more table scraps, nor rewarded begging.
Males are more likely to dominate than bitches, and castration reliably reduces dominance. Progestogens (pills or an injection from the Vet) can also be helpful in the short term.
Don’t seek unnecessary confrontation, and if grooming, nail clipping or similar activities are unavoidable, first muzzle the dog.
Dominant dogs can be enjoyable characters, memorable for their spirit, so long as you remain in control.