I am glad to hear your Mack is doing well...I wish I could say the same for the boxer-shepard mix we adopted a few months ago. I read your post because ours too is very vocal-he barks at everything, literally. We can't mow the grass, rake, sweep, mop, vaccumm without him barking. My fiance is a smoker and everytime he lights up Bower barks crazy at him-he knows it isn't good, why can't my fiance' figure it out ? Bower also barks at me when he's hungry, thirsty or wanting to play and it's nice that he can tell me when he needs something but when he gets into trouble he likes talking back. So I have read this book called "The Latchkey Dog" and I will be alpha but at this time it seems as if fiance' is alpha. Bower really listens to Tom well but Tom works 12 hour days and isn't home much so Bower gets loud quite often with me. Usually during the day he is fine with me, always wants to cuddle and be by my side BUT when company comes over he acts up something serious. So I often though he was trying to compete for my attention and when I give him total attention he calms down some but not totally. I want to take him to obedience training but don't think I can until I can ensure he won't bark furiously at someone or nip at them. The one thing I don't understand is he LOVES other dogs AND cats but acts like he doesn't like some people. I get scared of his nipping and don't know what to do when he does it. For example the other day I was messing around at him and he jumped up and got my face-he didn't bite down and it didn't leave any marks nor did it hurt. I said "ouch!" and immediately he layed down and hid his face like he was ashamed or apologizing. If he nips like that when he's playing, how can I be sure he won't bite as an adult dog? I love him so much and am willing to do whatever it takes to stop these bad habits-I need to gain control but everything the books tell me to do doesn't work, he just barks back at me. I have tried ignoring, turning my back and even my vet has shown me some restraint methods when he gets crazy mean but its like putting a bandaid on a severed arm it seems.
Anyhow, good luck to you and Mack and in the meantime I think I will reread my latchkey dog book because I am determined to be the Alpha gosh darn it