Have a dog w/allergies and the only commercial dry chow he's been able to tolerate and thrive on is Go Salmon. Can't have chicken or turkey or beef or pork or veal or lamb. Made homemade w/all those meat (things never improved w/the homemade) , as well as doing several months of the BARF diet for him. (for our husky it was great, for allergy dog it was disastrous).
We mix in pumpkin puree with the dry chow every day to keep the dogs' weights down (both of our dogs would eat themselves into oblivion if we let the, the pumpkin makes them feel full without getting too many calories for their ideal weights), and several times a week we add some yogurt, brewer's yeast, and garlic.
Go is very expensive (almost $45/a big bag), but it has drastically cut down on our vet visits and bills, so we're gonna stick with it. Our dogs are 9 and 10 years old and act like puppies still, the big galoots. One is a husky/malamute mix, the big guy is a St. Bernard/shepherd mix.
Big Guy also had some behavior/temperment probs that weren't solved w/ behavioral interventions, so he's also on 20 mg of Prozac/day! Since he got on meds and GO Salmon, those probs are gone.

MZ