Cockapoo dog food

Question
i currently own a 8 month old cockapoo.  He does have a girdia parasite that we have been trying to get rid of for
the past 4 months.  The vet has tried many different medicines. We are going to test him again in another month.  However he does burp alot and has a very sensitive stomach.  I have him on Natures Variety diet. He likes all the types:  beef, chicken, liver, salmon. I do give him 1 tablespoon of moist food with his kibble for breakfast.  I feed him twice a day. 3/4 cup kibble.  
Is there any food that would be more gentle on his stomach or is this the best food?
Thank you,

Answer
You would do better to pick a variety and stick with it.  Changing a dog's diet can upset its stomach.  If you continue to have problems, your vet might be the best source of info on another chow.  Although many of them will steer you to the Science diet they sell, most of the formulations do an excellent job.