Why are you concerned with grain free??? Absent a true allergy to corn, wheat or soy there is no proven benefit to grain free in dogs (or cats for that matter). Apparently Blue Buffalo has done a good job marketing.
The grains do add calories, but adjusting amounts is usually all that is needed.
Find a food that your dog does well on and is readily available and you should be good to go.
Doug, DVM
Oh boy, here we go again with a food thread.
Doug & Sandy
Kaylee
Winnie 6 1/2 year old golden
2008 Southwind 2009 Honda CRV