My girls eat Dick Van Patten's Natural Balance Duck and Potato Small Breed Bites. WHEW that is a mouthful
They have several Grain Free varieties (they call them Limited Ingredient Diets). The Duck and Potato is the only one I've found in the smaller bites, but the regular size bites are okay too because they are flat, so not hard to chew for most doggies. I get the small bites because my Luna has a pretty bad overbite, and was having a hard time with the larger pieces.
Good luck!!!!