Many thanks for all the post and links. A behaviorist/trainer visited yesterday, and we're now working on a few things.

The one thing, however, that feels a little bit hopeless is his over-sensitivity to noises outside, such as when people pass, or a car door closes. He still explodes from the kitchen at even the slightest sound and races to the front door barking.

The trainer suggested a barrier in the hallway to shorten the distance and also distraction techniques, but he's super hard to distract once he hears the sound and I fear he'll just learn to bark by the barrier instead.

He doesn't respond to commands, and he has no interest in treats once he's 'in the zone', and trying to beckon him back seems to make him more aroused.

Anyone have any tips on this particular problem?