This was written by Ellie's nutritionist:
Frequently-Asked Question
Since she is so small I'd be worried to use that method and I really don't like any dog food, so I can't recommend one and feel comfortable with it.
I will say no Nutro, Eukanuma, Iams, Purina, Pedigree, Merrick (qualiy control issues), Royal Canin (unless vet diet) or Science Diet (unless vet diet or possibly Nature's Best).
Maybe try talking to a nutritionist and seeing if they have ideas before switching back?