why is my papillion shedding too much?

my papillon is a female, and 3 1/2 years old. i brush her everyday, and still sheds like crazy. i had a allergy test (food) done, the vet told me they would send it to Spectrum labs, as i requested but they sent it to Heska labs. it was a straight forward result report.(meaning they responded YES OR NO to being allergic) all food choices being NO. Spectrum on the other hand give a negative 0-99, and positive 100-5000. if Heska had given me a number close to 100, i could have tried to eliminate the ones close to 100, but as far as i am concerned they gave me a brush off report. if they really did the lab work, how much more trouble would it have been to put in the numbers ?? it still begs the question WHY is she shedding this much. she gets no staph infections, but does bite herself, and her feet, and scratches. any information would be greatly appreciated. Guy