I was going to say vasculitis, which can happen after a vaccine is given - this can sometimes cause a permanent or temp bare patch. But, you said it's not btwn the shoulders, so I kind of doubt it's that.
It could be ringworm. My Marcel caught ringworm from his vet when he was a puppy, and it looked similar to this. Glad you're taking her to the vet so you can find out for sure. Keep us posted.
__________________ ~ A friend told me I was delusional. I nearly fell off my unicorn. ~ °¨¨¨°ºOº°¨¨¨° Ann | Pfeiffer | Marcel Verdel Purcell | Wylie | Artie °¨¨¨°ºOº°¨¨¨° |