That's the one I saw (and have by the way)!A cream named Protecta-Pad is used for paw pads and elbows. It has a spearmint smell and my dog runs when I come near his front feet with the cream! It should soften up the calloused elbow and maybe hair will grow there again. Yes, it was probably the concrete floor that created her callous.
I think some dogs even in great indoor homes do get them, just from the way they lay. I think Dillon came with his, didn't he?