Diagnostic tests are needed to recognize food allergy and exclude other diseases that may cause similar symptoms. Tests may include: A complete medical history and physical examination. Your veterinarian will examine the skin closely and inquire about your dog's dietary history. However, most animals that develop food allergy have not had a recent change in diet and have been eating the same food for a long period of time.
An elimination food trial. This test consists of identifying a diet that contains ingredients to which the pet has never been exposed and strict feeding of this food alone for 8 to 12 weeks. Food allergy is considered a possibility if the itchiness and scratching subside and your dog does not develop relapsing skin or ear infections during the food trial.
Treatment for food allergy may include one or more of the following:
Avoidance of the offending food or food ingredient
Antihistamines to decrease the itching
A newer therapy called Oclacitinib (Apoquel) has been very effective in control of itching in dogs with food allergies.
Treatment of secondary bacterial or yeast infections
New food allergies can develop over time. If your dog was diagnosed previously with food allergy and has been well controlled with a special diet but once again is showing signs of allergic skin disease, he may have developed a new allergy. Under these circumstances, consult your veterinarian to determine whether a new allergy has developed or whether another disease is present.
Another elimination food trial may be necessary to make this distinction. Patience and determination are important for the success of an elimination food trial. You and your family must be strict and be certain that no one "breaks" the food trial by giving the dog treats or table scraps. Strict compliance with the trial is essential for proper interpretation of the results. This means no treats like milk bones, rawhide bones or pig ears, no flavored medications (Heartgard Plus), and no flavored vitamins during the trial.
A genetic predisposition seems to exist for food allergy. Based on their genetic constitution, some animals seem to be predisposed to development of food allergy. However, since the cause of food allergy is unknown, the disorder cannot be prevented.