I agree with the above posts about being assertive. While I am not a professional dog trainer, I have had enough dogs, or dealt with other dogs (OH, MY SWEET MYLES-see other thread) to know that the dog, when doing that, is testing you to see how you will react. If no reaction, then the behavior gets ramped up next time the situation arises. Believe it or not, I have also seen this "testing" with my cats! I deal with it all the same way:
1). Firm tap on the butt (or a mild spank for my big dog-gets their attention).
2). Look dog straight in the eyes.
3.) Say firmly: "Cut it out!"
4.) Keep looking at them until they look away (not glaring or being threatening, just keep a steady gaze).
5.) After the dog looks away, put it down without comment (praise too soon after intervention can be confusing).
When he is appropriately engaging, have a ball!
You could also try a "time out" space for him. I use this with my big dog, with good success.
Hope this helps. I have found that the main thing is to just let them know that this is not OK, regardless of no skin being broken, "he's just playing" etc... I went down that path with my big dog at first, when he was younger, and paid the price. Had to go back and undo all my indulgence, which was much harder to do. Now he NEVER attempts to take my body parts in his mouth for any reason. He would rather enjoy having his ball in his mouth than my hand, and having to go to time out. I have had much less success with doing this with my kitten, but cats are a WHOLE different game. I did teach him to fetch, tho... I love playing fetch with the kitten now!
