My little girl was getting really dry so I just started giving her a little salmon oil in her food, which was helping. I also talked with a breeder that shows her yorkies, they have beautiful coats, she feeds them Solid Gold dog food, I am in the process of switching over to that food, Solid Gold wee bits and also putting in the Solid gold sea meal which is a nutritional supplement and also aids in digestion, it helps them absorb all the nutrients.
My little Molly's hair has already started to look better and it has only been a couple of weeks. I love this food for my baby, the ingredients are all natural and its made in the USA, I have done a lot of research on dog food and this one is really great.
Also Silky show shampoo and conditioner from Espree is great. I know petco has both Solid gold and espree.
Good luck! I hope you can find what she needs.