
are you sure it was his food he was allergic to? i would expect a food change would have solved the problem if it was food that caused it. i wouldnt like the thoughts of my dog having anti histamines (sp) everyday.
if it were me after having the ears cleaned out by the vet i would take my dog to a friend or relatives house for the dog to live for a week, if things clear up in a new environment then you know its something in the house causing it, maybe a plant, wash powder etc and you can begin to eliminate things step by step. i know its not ideal but if it cures the dog then it must be worth it.
i may be wrong, but i thought natural yoghurt was to help the gut like people drinking actimel or yakult type thing.
im sure someone else will be able to help further
xx