What are the ingredients in the food you are currently feeding? Grains can be just as common a culprit as some of the common meats, so can soy.
To do an elimination diet, you should pick a good quality food that contains things you likely haven't fed your dog before. Wellness has 2 foods for allergies, one with duck, the other venison. I feel meat is further down the list than I'd want to see, but it could be a starting place to see if there is any improvement.
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