Natural Balance Duck and Potato can be used as a daily food and many Yorkies on YT thrive from it, so it's a good choice.
To the Original Poster:In my opinion some of the best foods include:
*Innova Small Bites
*Innova Evo (high protein/grainfree-some dogs do wonderfully including mine)
*Solid Gold (Wee Bits-available a Petco)
*Orijen (kibble is slightly larger, higher protein/grainfree)
*Wellness Small Breed Formula (Available at Petco)
*Nature's Variety Instinct (Chicken or Duck/Turkey Formula)
Good Luck