Brewer's yeast works great for skin and fleas. It works good for coats and helps ease itching. Just make sure the dog isn't allergic to yeast. My scooby is allergic to fleas and yeast. It takes a few days to get into their system but it works. It has made a huge difference in Dirtnap! He is an older Eskimo spitz and he is just looking and feeling better after being on it. He actually reminds me to give him his pills!!!
Good luck!!!