food allergies

Question
My dog, Rocky, is a 6 year old pug. His last vet visit was about 3 months ago. His current food is Hills Prescription diet z/d ultra allergen free. His current medications are Chlorphenarimine and Cyclosporine ophth. oint. His current medical concerns are food allergies and an eye disease (I dont remember what its called). How can we figure out what Rocky is allergic to? He has been eating allergen free dog food for a few months but still licks his paws and scratches his face, so why would he still have allergy symptoms when he is on an allergen free diet and nothing else but his allergy medicine, and our vet is pretty sure he has food allergies?

Answer
If he is still having problems on the Z/D, he may have more problems than food allergies.  The quickest and easiest way to identify the allergens is to have the vet run blood tests.  It isn't cheap.  You could look a what he was eating before and earlier.  The more different types of proteins he has eaten, the more different things he may be allergic to.  Look at foods that don't have the ingredients his older foods did.  Our daughter's Shepherd developed food allergies to Pro plan chicken and rice.  They tried the Z/D, but wanted money for them and their kids to eat too.  He is now on Pro Plan salmon and rice and doing fine.  Salmon and rice may not be the right food for your pug.  You may be pushed up to venison and potato or some of the grain free and limited ingredient foods.  Of course, the Z/D may be cheaper than some of them.  Look for the lower cost things different from his past diet first.  Allergies have nothing to do with the price.  If he is allergic to lamb, even the most expensive, grain free, free ranging organic lamb based food won't work.  A beef and barley one might.