My ex-boss/vet's advice has always been to steer clear of foods with cute names (Gravy Train, Kibbles N Bits, Mighty Dog, etc.)--she calls them "McDonald's for pets" and says a lot of them have too much sodium. She tells me Iams is the best brand sold in the grocery store. Purina One comes in second. Mine does really well on Nutro (Senior now that she's old). It's low-filler so her poops aren't as big, but it's not cheap so that may be a problem if you're feeding multiple dogs (I have one 35-lb. dog. Doesn't eat much).

I've never heard of a *good-quality* dry food being vitamin-deficient. I'm sure this was true at one time but pet foods have come a long way. However, if a dog will eat them, vegetables (apart from grapes, onions, and garlic) are good. Mine doesn't like plain veggies but loves frozen broccoli and green beans--sort of like chewy ice cubes.

We always fed white rice and boiled chicken for GI problems--bland but most dogs will still eat it. Mine spent a week on it a while back when she got a messy spirochete problem, until the antibiotics and Imodium kicked in.

LOw-sodium broth over the regular food sometimes works, and there are special "sauces" sold just for dogs. I don't know if they're OK for dogs with sensitive tummies, though.