No Chase was on science diet when I got him and Blizzard was on Purina puppy chow. And yes we switched them slowly. And they are never out of my sight so no they haven't gotten into anything and they don't have parasites they are on flea/tick treatment and heart guard. And Chase is highly allergic to wheat. And liver upsets Blizzard's tummyWere they both on the same food before that did agree with them, if so I would go back to that until you can find something. Did you change them over slowly? Have they been into something? Tested for parasites?
If not, there are a whole lot of foods out there. Is there something in particular you are looking for in a food? Grain free? Grain Inclusive? Specialty store vs Chain? Different protein? Special needs?
I know a lot of people, myself included, that have a hard time getting blue to work for their dogs so here's a good list to start by:
TOTW (Taste of the wild)