Acana Grasslands vs Ranchlands for Boston Terrier?

I have a female boston terrier she 6 months old. The purina beneful puppy growth formulas she has been eating gave her an allergic reaction. I have been researching dry dog foods and found this is a very good brand. I juat can't decide which of the two to pick? They are both grain, soy, and corn free which what i need.a lot of Boston terriers are allergic to those ingredients. So just to be safe I'm going to purchase food without them. Just having a tough time choosing. I think the ranchlands sounds better, but not completely. Any help would be great. Thank you all in advance.