I'm no expert on this type of behavior, but it's obvious he's feeling a bit higher up in the pack than he should be. I would really recommend a book I have that I have always found to be very good in dealing with various problem behaviors, "How to be Your Dog's Best Friend" by the Monks of New Skete. It really goes into how to assert yourself as the alpha by using the language wolves use in the wild.

If interested in finding more out about it, here's a link from Amazon that has the description/reviews etc.

http://www.amazon.com/exec/obidos/tg...glance&s=books

They heavily emphasize eye contact and the role it plays between the alpha and the other members of the "pack."

I wish the best of luck with Lefty. It might be a good idea to contact a behaviorist as well for some advice or even your vet, but then it seems everyone has different advice on how to hanlde these things. In the end you have to decide the course of action that you feel is best for you and Lefty.