DS: Shiny Coats and what floats your boat?

Well my sister's dog is 12 years old and has always had a dull coat full of dandruff and it itched him all the time. I finally convinced her to add olive oil to his food and his coat looked better but he still itched. I told her to put him on a better food....one with no wheat, corn or soy. She did and I saw him Sunday and I could not believe how shiny and soft his coat was! The change in food made all the difference with his coat.