How to figure out what food your dog is allergic to?

The best and most accurate method of diagnosing a food allergy is to feed a hypoallergenic diet for 8 to 12 weeks as a food trial, called an elimination trial. To be a true elimination trial, this special diet must not contain any ingredients that your dog has eaten in the past. It also requires that no other foods, treats, or supplements are fed during the trial period, including flavored vitamins and certain parasite preventives. If your dog's allergy symptoms resolve while on the food trial, the next step is to perform a food challenge by re-introducing your dog's old food. If your dog's symptoms resolve with the food trial and return within one week of a food challenge, your dog has been definitively diagnosed with a food allergy. The most common food allergens in dogs are proteins, especially those from dairy, beef, chicken, chicken eggs, soy, or wheat gluten. Virtually any food ingredient can produce an allergy, however. Proteins are the most common culprits but other substances and additives can also be responsible. Once the offending food substance has been identified, a diet that does not contain it is chosen.

If your dog has GI and skin allergy symptoms, your veterinarian will likely suspect a food allergy over other potential allergies. They might prescribe an elimination diet, which is considered the gold standard in determining if a pet has a food allergy. With an elimination diet, you veterinarian can switch your canine’s food to a hydrolyzed formula to see if their condition improves. For a period of at least 4-12 weeks, no other food, treats or flavored supplements can be eaten. If the clinical signs subside, then you can re-challenge your pet by steadily introducing other ingredients back into their diet and observing how they react. Your veterinarian can help you sort through the symptoms and pinpoint the cause. Once you and your veterinarian have identified the source of your dog’s food allergy, you can discuss options that are free of the ingredient that causes the reactions.