Food allergies are quite rare, so are you/the vet sure his allergy is to food? If not, I'm not sure I'd choose to feed this food until I had clarification. Did you try an elimination diet or anything? If it's an enviro allergy, you then usually medicate rather than switch foods....although it can be a good idea to have an allergy dog on a lower carb diet as it can help decrease some of the inflammation.   
What meds have you tried so far?     
				__________________  ~ A friend told me I was delusional. I nearly fell off my unicorn.  ~    °¨¨¨°ºOº°¨¨¨° Ann | Pfeiffer | Marcel Verdel Purcell | Wylie | Artie  °¨¨¨°ºOº°¨¨¨°      |