It would be nice if there was but there isn't.
Everyone has their own ideas of how much protein is good for Yorkies, etc.
I can only tell you that I think protein in the teens is too low for a healthy dog and 21% is about the lowest I'd want to go. Mid 20s seems better to me though. I wouldn't want to give something much more than 28-30% protein but have no scientific research to back up my position. Personaly preference...
I think foods with 25-30% fat are much too high for Yorkies and prefer something 18-20% or under. At the same time I see foods for all life stages with a fat content under 10% and that I think is just too low for pups but again, my opinion.
I'm pretty sure this did not help you but there you go.
