Yeah highway is the only thing that's really similar, she does have Yellowbelly which is halfway to highway, so maybe something is interacting with the Yellowbelly. It hadn't occurred to me before that the dashes on a highway correspond to the dorsal blotches, just much thinner. It sounds kind of obvious when I say it that way, but if you picture her yellow areas being much darker you can see how a highway pattern would emerge.
And yeah, weird stripe is much better than her hurting her back, I wasn't sure what I was going to do if she was scraping herself. She's a very active girl but is getting much better at sitting quietly with me for awhile - she's curled up in my sweatshirt pocket here.