chihuahua yeast ear infection

Question
We have a one year old chihuahua who is on his 3rd ear infection.  The vet says he will always have trouble with this ear and we need to clean it twice a week.  We have been doing that and he is now sick again.  Any chance that he is allergic to something in his food?  (We give him Beneful Puppy)  and if so, what food do you recommend?  We have tried Purina Sensitive Stomach and he won't eat it at all.  Thank you in advance.

Answer
I agree that in a young puppy with yeast infections, a food hypersensitivity is likely.  There is a food called z/d ultra that I would recommend to test for a food allergy.  Feed this exclusively with nothing else getting into the puppy for 6-8 weeks. YOu will know if there is a food allergy if the puppy gets well over that time. Flushing the ear helps keep the yeast numbers down, but theyeast is secondary to some type of allergic skin disease.