Red Inflamed Cuticle My Dogs Butt Is Red And Inflamed?

My dogs butt is red and inflamed? - red inflamed cuticle

Yesterday I realized that my dog was "Scooter" hes never done. Anyway, I saw, and her ass is very red and inflamed. I called my vet who said to bring, but I thought I would first ask whether anyone an idea what it might be, or if anyone knows of one had been on non-prescription medicines that could be gained. Thank you!