Wow! Jake seems to be about 3/4's back to normal at this point.
He was asleep in his kennel this evening when we went out with friends for a couple of hours...so we closed and locked the door on the kennel so we would not wander around the house without us there.
When we got home a couple of hours later, and pulled into the garage, my wife immediately noticed him barking which he hasn't done at all since this "episode" began on Wednesday.
I ran into the house and he was just going berzerk in his kennel...it was like he sort of "snapped out of it" and realized he was locked in his kennel and was really upset about it.
I unlocked the door and he bounced out wagging his tail furiously and licking me, something he also hasn't done since Wednesday. He literally BOUNCED and RAN around the kitchen (he was just sort of padding around the house aimlessly and seemed to barely be able to keep his balance for the last 3-4 days) and then he headed for the front door to be let out to do his business.
He then proceeded to do his normal front yard patrol sniffing to see what other dogs had been by, etc. He was previously not interested in doing any of this.
I say he is only 3/4's back to normal because he still wandered around the house sort of like he has been doing but at a much faster clip and not looking as "confused" as he has been...almost like he was really getting to know the house all over again. He only made about 3 circuits of the house and then laid down contentedly. Before, he would pace the house for hours upon hours making the exact same path through all the downstairs rooms.
He is still reluctant to jump up on the couch with us...like he is still uncertain about jumping, his balance, or possibly gauging the effort involved. About 3 years ago he started getting a little stiff and I actually taught him to "back up and get a running start" in order to make it up on the couch or the bed. He obviously still remembers and understands that because he responded to my verbal command and hand motion for "backup and jump" but he wouldn't follow thru with the jump itself, instead deciding to just lay down in front of the couch.
I am so thankful for all the good advice and the encouragement given by everyone on these threads. I am sure it all worked together to help get the little guy back from what seemed like the brink.
Kris