Your girl is beautiful!
I know that I am coming late to this discussion, so I apologize. I have a half dogo/half American Bulldog grand-puppy, AND, YES, SKIN PROBLEMS. We use for the grand-puppies and for my mastiff, the IAMS Skin and Coat Plus which is basically a potato and fish product. I have heard, unfortunately, that they won't be making it anymore and are suggesting the fish and rice formula. NOW, I HAVEN'T CHECKED THIS OUT MYSELF, So, I don't know if the rumor is true. Perhaps I have been misinformed. If it will still be available, I'd suggest that you try it. It has worked well for us and all the skin situations were resolved. No more upset stomachs, no more rashes. Just happy pups.
By the way, my daughter cuts up and gives raw sweet potato for treats. The dogs love them.