I feed a multi-protien diet myself...Sally does well on" Evo," but only gets an 1/4 cup in the am and gets 1/3 can of" by nature organics", and then she gets small bites of whatever we are having at mealtime. Just no cooked fat or sugary things. She gets American made turkey jerky and does great on all this. Has NEVER had diarrhea and has vomited 3 times in 3 years and 1 of those times I induced vom. b/c I thought she may have eaten a mushroom growing in our yard. The cat on the other hand has a funky gut and I feed BB tukey/pot. and1/2 can "by nature Turkey" for cats and she does great-no yaking or poop puddles. Her fur has grown back in all over-she had bald legs at one time and I wasn't for sure if it was food or habit or combo of both. Definatley a good idea to expose gut to as much as it can handle,but I would watch fats b/c of pancreantitis, every dog is different and like people, some are more prone to allergy. Maybe digestive enzymes as someone mentoned,I think, and a probiotic would help aid digestion some. If you are able you can make your own bland diet of boiled chix/rice and gradully just add whatever food you want to try to that so that you don't have to buy the food from your vet. Watch the treats and where they are made b/c of unsafe ingredients too.