To diagnose a dog with food allergy, the first thing to do is put the patient on an elimination diet, or an “exclusive novel protein diet. This ends up being a diet with individual ingredients to which the dog has rarely ever consumed before. Usually, the diet is commercially prepared and fed for a minimum of eight weeks.
The goal is to determine if food is a component of the itching.
Typically dogs are allergic to proteins they are exposed to for extended periods of time. In the United States, dogs are generally allergic to beef, chicken, and egg protein.
Patterson explained that most elimination diets replace beef, chicken, and egg based foods with an exotic meat protein like venison, duck, kangaroo, or vegetable-based. After eight weeks, the patient is “challenged” by returning to the original diet.
If the dog’s symptoms (itch) improved during the eight weeks, then return when the dog’s original diet is replaced, then a food allergy is confirmed.
“Patients with food allergies typically relapse within two weeks of returning to the original diet,” Patterson said. “It is important during the elimination diet to remove any flavored medicines or supplements, table scraps, typical treats, rawhides, and pill pockets from the animal’s diet so the test isn’t compromised.”
If a commercially prepared novel protein diet is not sufficient, a prescription hydrolyzed diet may be necessary. This food is only available by prescription from a veterinarian. It helps dogs with food allergies by breaking down the protein into small enough fragments that the immune system cannot recognize it, and, therefore, does not induce a skin reaction.
Another option for dogs with food allergies is a limited ingredient home-cooked diet. Patterson recommends only doing this under close supervision of a veterinarian.
While any breed is susceptible to food allergies, Patterson sees many poodles, boxers, weimaraner, dachshunds, chocolate labs, and German shepherds with food allergies. He has also noticed dogs with German lineages tend to be more susceptible to food allergies.
Generally dogs diagnosed with food allergies can remain on commercially prepared elimination diets for life without complications.
“As with any skin disease, there really isn’t a cure,” Patterson said. “Instead, proper management of the disease can keep dogs happy and healthy lifelong.”
Pet Talk is a service of the College of Veterinary Medicine & Biomedical Sciences, Texas A&M University.