Dog Food for Shih Tzu

We have a 7 week old male Shih Tzu pup. We currently feed him on Purina Beta Puppy Dry food (Lamb and Rice). We give him approx a palm full 3-4 times a day he will eat approx half of each portion. Can anyone recommend any other products we could try. Also can we give him any treats if so can anyone recommend any.