In many cases, this is just a matter of attention seeking behavior, which in and of itself is completely harmless and often amusing. Boxers learn quickly what gets your attention. They are swift students when it comes to figuring out what will wake you up or what will bring about a smile or a laugh. Some behaviors and actions are a way of saying, "Hey, do you see me here? Say you see me!"
And even if you jokingly toss a pillow at your Boxer, he/she will get the answer that they are seeking. And be assured, your dog WILL ask again later in the day!
Once your Boxer has learned that shaking his head at you either wakes you up or gets you to talk to him, that's it! He or she will keep doing it. Many Boxers will make this a daily ritual. You're snoozing away. Your dog is awake and wants you to be up too… And it starts. He'll crawl up close and starting shaking his head into your face.
For dogs with natural,
un-cropped ears, this is compared to having a miniature helicopter in your face, as the quick back and forth motion creates a whirling bird of ear leather slapping at you! What can you do but learn to love it!
The only time you would want to instill training to stop this is if a dog shakes his head into the face of a young child and it is either causing the child to be fearful or is a discomfort to them; however this is very rare since this breed has a natural instinct to protect his human sibling counterparts… The Boxer breed is terrific with children and most naturally do not act out in a way that frightens or causes harm.
One thing is for certain, the Boxer breed expresses their emotions and when all is said and done, that's a great element to have with your canine family member. So many Boxers do this that one could almost list it as a breed trait.
Some Boxer dogs will shake their heads as a signal for special action. It is not uncommon for this to happen if a dog needs to go outside for bathroom needs, so do pay attention to see when this occurs and if it is a sign.
For others, this may not be done for attention, but rather as part of the sleeping process. A Boxer may shake his head when he wakes up (a physical manifestation of 'shaking your brain awake') and less frequently, this may be done before falling asleep.
As long as you do not see any signs of medical problems (discussed ahead), consider this to be harmless.
Quick note:
In multiple dog households, it is not uncommon for one dog to quickly pick up the habits of another… So, if you have two Boxers (or a Boxer and another dog), they may shake their heads in unison. Having dogs that are bonded enough to act silly is a pretty great thing and since this is harmless, you mind as well find the humor in it.