Yesterday I noticed a good-sized (approx. half inch round) scab on the shoulder blade of my 1-year-old tortie, Noodle. This has happened one other time as well. I wonder what would have caused this.. ? Our cats are indoors.. however I recently gave them home flea treatments on the backs of their necks.. so it could be an allergic reaction. Has anyone encountered a similar problem, and what should I do? She doesn't seem to be bothered by it at all.