This article is from the Canine Allergies FAQ, by Cheryl Minnier with numerous contributions by others.
The previous section of this article dealt with atopy or inhalant
allergies. This article will deal with food allergies or to be more
precise, food sensitivities. Much of the information presented here is
drawn from "Hair and Skincoat Problems in the Dog" by Lowell Ackerman
D.V.M. and an interview with Dr. Scott Krick of the VCA Sinking Spring
Veterinary Hospital. Food allergies account for only about 10% of
allergy problems in dogs, however they are easily treated so it makes
sense to test for them if you suspect they may be the culprit of your
dog's skin problems.
Like inhalant allergies, food sensitivities primarily manifest
themselves with itchy skin. Other symptoms include anal itching,
shaking of the head, ear inflammations, licking front paws, rubbing
faces on carpeting and rarely vomiting, diarrhea, flatulence,
sneezing, asthma like symptoms, behavioral changes or seizures. Many
people don't suspect food allergies as the cause of their dog's
itching because their pet has been fed the same food all its life and
has just recently started having symptoms. However, animals can
develop allergies to a substance over time, so this fact does not rule
out food allergies. Another common misconception is that dogs are only
sensitive to poor quality food. If the dog is allergic to an
ingredient it doesn't matter whether it is in premium food or the most
inexpensive brand on the market. One advantage to premium foods is
that some avoid common fillers that are often implicated in allergic
reactions.
 
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