Hi All - quick update - I have padlocked all of the gates. Moved my patio furniture against the fence where most of the "action" happens - since I'm painting and weeding and doing other things, it doesn't look too strange but also keeps the dogs apart. I've also moved a bunch of plants against the fence further up the fence line. This looks like it will keep the dogs separated for the most part, and half of it looks normal (the plants) and I don't care about the chairs up the fence for now.
I spoke with my realtor today as well - he's of the mindset that we cross the bridge of confronting the neighbor only if it becomes necessary. He thinks that the neighbor is unlikely to confront potential buyers when they are there with their buyer's agent, and that if it does happen, the buyer's agent is likely to let us know so we can deal with it ASAP.
We visited a few homes today and I found my future home, assuming everything works out. I'll be focusing my efforts over the next several days on getting the last issues at my place resolved so we can list next week.
To those asking about my dog or myself - my dog is incredibly nice but perhaps not the smartest in the world. She never barks (she has barked literally once in 3+ years, and only when she saw a rattlesnake - kind of helpful), is fantastic around people, very well behaved overall, but (I think) is very lonely, so anytime a dog is near she wants to get as close as possible. When around dogs, she appears to want to be the alpha female (or even just alpha dog). But she did live in the same house with another dog for over a month with only two relatively small fights (first day and about three weeks into the stay). The first was probably a draw and the second she clearly lost. She was whimpering all night long and I thought something was seriously wrong - called the vet and they said to give it 24 hours. 24 hours later she was fine...
As for me - I walk her twice a day, usually about a mile each time. I have not previously confronted the neighbor or called animal control because I truly believe the neighbor will poison or otherwise harm my dog in retribution for anything I do. While you may disagree with me (and you may very well be correct), I've chosen what I believe to be the better possible path to protect my dog long-term. Believe me, if I felt I could call animal control and my dog wouldn't be at risk from an unstable, unemployed neighbor with an ax to grind, I'd do so in a heartbeat.
The realtor says if I price the home the way I plan to, it should be under contract in three days. I doubt it, but if so, this unfortunate episode may be over before Thanksgiving.
As for boarding the dog - I hate to do so. She is queen of the house here and has a 1500 sq. ft house and a 1/2 acre fenced yard to roam about freely. A 5'x10' cage is pretty lame by comparison. If the house goes under contract before I go out of town, I'll hire a house sitter so she can stay at home. If it hasn't gone under contract before I have to leave, I'll reluctantly board her to make showings easier.
Apparently I'm not able to write anything without it being verbose - sorry. It's been a long week already and I'm exhausted and cautiously optimistic (too excited, actually) after seeing what I hope will be my (and my dog's) new home.
Thanks to everyone for your responses - I appreciate you taking the time to reply!