A good way to start looking for a good dog food is by going to :
www.dogfoodanalysis.com
The foods listed under 4 and 5 star categories are the foods recommended for yorkies

Make sure to check that they are not on the recall list. Also, you can look at the 1 and 2 star foods so you can compare. That way you can see why the 4 and 5 star foods are so much better. The lower quality foods use ethoxyquin, BHA, BHT, by-products and all kinds of stuff in the lower category foods. Ethoxyquin is actually a carcinogen that is banned from human foods, yet they allow it to go into dog foods