Starting them on the Blue Buffalo (while I would personally never use Blue Buffalo products) actually helped to give you more information. What you need to do is compare the ingredients in all of the foods they’ve eaten and reacted to see what common ingredient they might have. Through trial and error, and many, many different foods, I’ve determined that my dog reacts to all fish (including fish oil), chickpeas, lentils, flax, probably garlic and likely tomato. Keep in mind that what might be a problem for one dog might not be the problem for the other and dogs that have food intolerances frequently have more than one. Randomly choosing a brand’s food labelled ” hypoallergenic,” will do nothing to help your dog if he’s intolerant of the ingredients in it.
I would look for a truly limited ingredient food with a meat protein and a starch that your dogs haven’t eaten before and see how they do on that for a while. Nature’s Variety Instinct LID is one of the foods I’ve found that my dog does very well on. Keep in mind anything you offer them could be a problem; ie: treats and edible chews.
