*~* I just realized...that you mentioned that he WAS eating better on the previous food ??
When you switch over FROM a food that may have a few fillers and by~products in it...TO a premium food...some dogs have upset tummies over the change.
While they may eat better....seem MORE excited about their previous food...in REALITY...there is just better nutrition in a Premium Pet Food.
You are supposed to MIX the 2 food together.
Did you mix the previous food WITH the new lamb & rice brand that he is eating now ?
*~* Nikki