My Shih Tzu Puppy Has Dry Skin Although I Give Her Fish Oil Daily. She Has Dandruff Flakes On Her Coat After A Bath With Oatmeal Shampoo. What Can I Do To Treat Her Dry Skin?

Two of my Shih Tzus' had a skin problem and I read where sometimes certain processed dog foods causes their immune system to be off, or they can get an internal yeast bacteria build up.
I switched to foods without corn etc and feed them at least once a day fresh chicken or liver, rice and fresh veggies. Brushing them helps keep the dry skin clear also. I use Paul Mitchell Pet Shampoo for hot spots it has tea tree oil in it. I then use the Paul Mitchell oatmeal Pet conditioner.
Human or regular shampoos have a different chemical balance for humans and shouldn't be used on dogs. The alkaline in some shampoos can be drying. Continue the fish oil on the food it is very good for them. I also feed my pups a tablespoon of plain yogurt. The good bacteria in it can get their system back in balance. It takes awhile for it to clear up but you should start seeing a change in about a month.