How do I get my blue heeler to quit nipping my heels!!

I know that sounds stupid because he is a heeler an it is in him naturally to be a bit nippy but he has a job and he knows it he works horses daily teaching them to load and pick up there paces. but he doesnt know when to quit!!! He loves his job(which he is really good at) but i dont know how to get him to stop!!! he only does it to me and ive tried the pinning him down like the dominate dog would do but as soon as you correct him he stops for a few seconds and goes lays down then as soon as you stop watchong him he will start nipping again. how can get to stop!! Please Help!!

Could you please explain to me what "dominate dog" and "nipping heels" means here?

Though I guess "nipping my heels" means "licking my heels".

Source : http://answers.yahoo.com/question/index?qid=20071230204432AAgLlpe
"nipping my heels" = biting my heels (small, sharp bites, or motions to bite).

I imagine that "dominate dog" is supposed to be "dominant dog" (the text is littered with mistakes).