Oh, that's such a neat story, what a special little boy. You mentioned getting a collar for after surgery, and I just wanted to let you know that many members have used a baby's onesie, similar to this:
http://www.sandboxcouture.com/baby-onesies-all.html you can get the plain white ones at Walmart, and I imagine they're much more comfortable than a collar. Glad to hear about the fence, you just can't be too careful. She is a real doll, and I'm so glad things worked out so well.
About your other question, How old is Little Man? You might want to start a separate question in the breeding forum for this question. I know Joey was doing things like this when he was 3 months old with a little pup that was even younger, and it is a dominance thing, but you might want to check with an expert.