As far as the best food, it’s really up to you. With the controversy over cardiac problems with some foods, I personally avoid grain-freed and legumes for now. I’ve put my dogs on a less perfect food (but still good) because of that (Purina salmon sensitive stomach).
I switched to the same thing Dechi's feeding but what I consider to be a little on the weak side as far as ingredients goes. But one: it's incredibly hard to find a grain inclusive, potato, legume, peas (which is a legume) and pulses dog food these days. Everything on the shelves of the Petco store is labeled grain free and big pictures of peas. When are these food companies going to get the picture and start formulating food with lots of animal protein and no peas!? Grrr. It's very difficult. I like the looks of Victor. They've ever had a recall. They make a very good formula. But one of my dogs is sensitive...has had a little trouble with that one causing indigestion. The others were fine on it. I'd say to try that first because it's not one named in this suspicion list for DCM and the ingredients are very good. (as far as a commercial food goes. lol) Take a look: https://victorpetfood.com/products/hi-pro-plus But just this formula. Some of the others are grain free and have peas. I'm sure some peas would be okay. But I am looking for foods that have none because how do you know how much they're putting in?
Did you notice that the Pro plan for sensitive stomachs and skin for toy breeds has some peas but the same one that is just "adult" (not for toy breeds) does not have peas. The kibble is still doable but it's a tad larger than the one for toys.