Diet Needs

I have a question about Grain or No Grain. I have finally found a pet food that seems to fit the bill of being a good product, but I have to decide on which product of theirs I wish to buy.. There is grain,, no grain,, and raw.. I"m sooo confussed,, I had no idea feeding my pup was going to be a science project... I sucked at science. She's a shih tzu, not sure if breed makes a difference,, oh yeah,, do small dogs require different things than average or big dogs? Help Please,, I need a science teacher.

I presume this is the Nature's Variety brand. I would go with the raw or grain-free formulas. Dogs do not need grains imo......they are mainly used as a cheaper source of protein.

with their teeth issues, try raw for cleaning. errrrrr... what food?