I have a Boston that used to have chronic yeast infections in her ears. I moved her over to a grain free diet and fed probiotics with great success. This cleaned up what no topical thingy every could. The food I feed is "Taste of the Wild" and I've have very good luck with it. Evo is also a great food, but I've noticed recently that it has become quite expensive. Grain free is such a hot trend in the dog food world that it should be relatively easy to find some. I have also made my own dog food and I would say the very best thing to help dogs with yeast and digestion (because they do go hand in hand) is tripe. Some folks can't stand the smell, but it doesn't bother me. Smells like a cow, which is an herbivore. I feed mine fresh tripe (green, not the bleached white stuff) but you can also get it in a can.
