NutroMax contains ALOT of allergens, so switching may alleviate many problems. You could try Canidae, Orijen, Innova, Innova EVO, Wellness, California Natural, Evangers.
Here is a great site to learn about dog food. Look in the 5 & 6 star sections for good foods.
http://www.dogfoodanalysis.com/dog_f...iews/index.php