I've been spending some time outdoors alone with Hachi, having realized that he's really nervous when the Duo isn't with him. I did do solo walks with him throughout his puppyhood but it seems that his fear of being the only canine has grown anyway.
On one of these outings, we found where the rising sun hits the drying grass on our land. Hachi is already amazingly well behaved when I want to take photos of him. He understands "stay" really well, and he swivels his head around as things (or smells) catch his attention. This head-swiveling is called "hypervigilance" by his behavioral vet - it's a symptom of his anxiety but it also makes for nice photos.
Then, a smell caught his attention. When we walked away from this spot, I saw 6 deer fleeing just upwind of this spot. Hachi was so good to stay!
This week, the vet increased one of Hachi's short-acting anti-anxiety meds. We humans think that Hachi generally seems calmer. However, I have seen more incidents than usual of Hachi acting aggressive toward R. Increased aggression is a side-effect of this med so we'll have to keep an eye on this tradeoff. It's interesting to realize that aggression is controlled chemically - it makes me less upset with Hachi himself when he's aggressive, and it makes me more hopeful that we can get his chemistry right someday.
I am feeling more patience about this process this week. We have the management side of the equation (i.e., keeping R safe) working well so it's okay if Hachi's behavior backslides a little as we try out new meds.