I am not an expert by any means but I look for meat...the more the better. For example the 1st 4 ingredients of my pup's food (Innova EVO) are Turkey, Chicken, Turkey Meal, & Chicken Meal. Some good grains are Barley, Brown Rice, Oatmeal etc. I also look for fruits and vegetables in kibble. You might want to start a new thread for input, there are tons on here in this section if you look back further. Many people feed grainless kibble (including myself) and many feed all sorts of other kibble. No Yorkie is the same, and people have had long debates about food. Much luck to you... and check out
Dog Food Analysis - Reviews of kibble Not a website to live by, but good for guidance!!