I asked Sabine about the reliability of blood tests for food allergies. Here's her response...
"Pretty hit and miss, unfortunately.
Especially since there's a major difference between actual allergies (where an inappropriate immune response *is* present) and sensitivities - which can cause very similar symptoms, but the underlying cause is different.
I've had dogs who did well on food items they actually tested "allergic" for and theoretically should not even tolerate.
IMO, a properly conducted elimination diet (*not* using some hypoalelrgenic prescription food, but real, fresh food cooked at home) is the very best way to determine what works and what doesn't work for an individual dog."
I then asked her, if someone wants to do an elimination diet they have to start with your prescribed home cooked diet. Here's her response...
"For the duration of the elimination diet, yes, since the idea is to eliminate all "unknowns", including all the commercial additives that may be present in store bought foods.
Some people may decide to try going back to feeding commercial products once they know what works and what doesn't, and often it will be ok for the dog that way, but for the really sensitive individuals it might turn out that they need to stay on minimally processed homemade food because they don't react to a specific ingredient (e.g. chicken, or oats etc.) but just can't tolerate highly processed food."
I then commented how environmental allergies seem to be worse trying to diagnose. And here is her reply...
"I agree, environmental allergies are an even worse nightmare to deal with. Quigley has some seasonal issues, but luckily this year nothing has cropped up yet and last year it was really mild. Usually it starts around the beginning of May (red belly skin, itching) and goes away once July comes along.
For him, more frequent bathing and occasionally some benadryl usually do the trick during that time, but I know of some dogs who have severe issues year-round."
If you can't get a grip on it, consider a consultation with Sabine. She deals with dog food allergies on a regular basis. Or consider a test at Hemopet Jean Dodds organization.