Hi Lauren,
I think I’d take a look at doing a true elimination diet if I were you.
Since you’ve been working with your vet on identifying your pup’s food sensitivities, you could talk to them about it and get your instructions from them. Essentially, you choose a single protein and a single starch that your dog hasn’t eaten before and feed only that. After you’re dog’s condition has settled down, you slowly introduce other ingredients, one at a time. If he reacts, you withdraw the food and continue with your single starch and protein. If not done properly, you’ll end up with inaccurate results. If done properly, it’s the gold standard for identifying food sensitivities / allergies.
Some folks will use raw or cooked foods, prepared at home. Others will choose prescription foods from the vet. Either way, it’s not forever, but it’ll help you get some answers.
With my food sensitive dog, I have better luck with Nature’s Variety Instinct Limited Ingredient Diets.
Good luck! I know how frustrating it can be!
