if he is still on meds it will do no good to give him anything to get the gut floral back to where it needs to be, so as soon as those are done try to get him to take some yogart ansd use them goat probotics.
Why didn't your vet run cultures on your bird right off the bat? that confuses me a...
Glad he is getting better. You have done a great job
I would like to say that feeding whole foods when he has been on these meds is probably not a good idea, his system has been flushed of the good and bad bacteria from the meds and he needs them to digest foods as well as grit in his...
Make him some soft food, scrambled eggs are good as long as they are not on a sulfer baised med.
when my peas get hurt they act sick and will not eat but if i cook them scrambeled eggs they can get that down.
Course they get scrambled eggs and oatmeal for breakfast now that it is colder