Maybe adding probiotics to the diet would help? You can sprinkle some on their food or even offer a little plain yogurt daily. Mine love a few licks of yogurt!
Recently, CeCe was vomiting bile in the mornings. I asked the vet and she said it most likely due to empty stomach and recommended giving a snack before bed time.....seems to be working.
No real gastro problems, though. I feed Royal Canin with fresh veggies to CeCe and Sasha is on Hills LD with fresh veggies (she has liver shunt).