— Many dog owners work hard to make their pets comfortable and happy, so it can be frustrating when a dog is constantly itching and distressed.
Dr. Adam Patterson, clinical assistant professor and Chief of Dermatology at the Texas A&M College of Veterinary Medicine & Biomedical Sciences Small Animal Clinic, explained how some perpetually itchy dogs may suffer from food allergies.
“Food allergies in dogs present themselves quite differently than food allergies in humans,” Patterson said. “For instance a person who is allergic to shellfish may experience throat swelling and a possibly critical or fatal reaction, but in dogs the allergy is expressed through the skin and seen most often as itch.”
Dogs who itch, lick, chew, rub, bite, and scratch themselves year round, typically around the face, ears, armpits, groin, paws, and around the anus may be showing signs of a food allergy. Since itchy flare factors have an additive effect, it is important to eliminate other possible causes of itching.
First, it is necessary to eliminate any possibility that parasites, particularly fleas, are causing the dog to itch.
Likewise, the veterinarian should also look for signs of skin infections (bacteria and/or yeast). Secondly, the veterinarian will also determine if environmental factors are causing itchy skin. Dogs with year-round itch, who eat roughly the same diet yearlong, are frequently candidates for a food allergy diagnosis.
“There isn’t a conclusive clinical skin or blood [serum] test to see whether a dog has a food allergy,” Patterson said. “It’s like flipping a coin to determine whether the test is a true or false positive. Because of this, we have to base our diagnosis on the dog’s history, clinical signs of skin disease, and response to a food trial. The test for food allergies in dogs simply isn’t conclusive at this time, but we hope some of our research will lead to an effective test.”