Well, Pepper's blood work is all normal except for one level that "basically indicates a stress response" and it was sky high, unsurprisingly. Her blood pressure and heart rate were both high as well. So chemically she's an anxiety dog but the vet didn't feel like her physical reactions were bad enough to put her on Prozac.
I ordered her a DAP collar and she gave me an anxiety protocol from one of her textbooks to work through. We sent off a full thyroid panel but she doesn't expect anything to come back from that, although she agrees with me that her coat and skin quality isn't very good and there's no real obvious reason for that. I'm switching Payton onto a high protein/high fat food so decided to put Pepper on that as well and see if that helps.
Said in some ways it sounds like she is having focal seizures, but it also doesn't, because if I call her name she simply snaps out of it, which isn't usually the case with focal seizures. And none of the other dogs are reacting like she had a seizure, and I'm pretty confident if she had a seizure Auggie at least would be like "hey something's wrong with Pepper." He hasn't done that.
She did say she really thinks if we spay her, some of this behavior will stop - that intact females can just be weird and goofy and once the hormones are gone they just quit being weird. I've been of that mindset for ages... so I asked her co-owner about it. And we'll see what she says. She hasn't responded to me yet. I'm not super excited to go through yet another surgery right after Georgie, but winter is the absolute best time to do it since we're not really doing any outdoor playing anyway.
So we have no real answers yet but at least it's not a brain tumor.