Just wondering what a callous looking place on a pup's leg could be. She's five wks old and I noticed when she was born there was a place around her ankle so to speak where one of her little wrinkles were that made her skin look pink and didn't think much of it but now it's bigger. They go to the vet next Tuesday for their shots and I'm having him look at this but in the meantime a little curious. All responses appreciated.