How to Perform a Food Trial for Your Pet’s Allergies

It should be noted that food allergy and food intolerance are two distinct conditions. Food allergy involves an adverse immune system reaction to an allergen in pet food, while food intolerance is a non-immunologic response to components in the diet. Food allergy triggers are usually the protein components of pet food, while food intolerance can be an adverse reaction to carbohydrates, artificial flavoring, dyes, and preservatives in pet food.

More than 75% of food allergy and food intolerance cases in dogs are associated with dairy products, chicken, beef, and wheat. In cats, the top food allergens are chicken, egg, dairy products, beef, and fish. These allergens account for more than 90% of all reported cases.

Pet Food Trial Basics

A complete food trial program involves the elimination, challenge, confirmation, and identification of allergens that may be causing your pet’s adverse reactions. The complete diagnostic food trial may last for months, the length of which depends to a large extent on the patient’s response to therapy and compliance of the pet parent.

Elimination involves giving a trial diet that does not contain the possible offending proteins. If there is an alleviation of allergy symptoms, your vet may recommend the next step which is a food challenge.

A food challenge involves re-introducing food and treats that your pet had before. If there is a flare-up of clinical symptoms, the next phase is confirmation.

Confirmation involves placing your pet on a strict elimination diet again. A resolution of the clinical symptoms confirms an adverse food reaction diagnosis.

The final phase of a food trial program is aimed at identifying the specific ingredient in pet food that is causing a flare-up of allergy symptoms so it can be avoided. This involves continuing the strict elimination diet and gradually offering small amounts of previously fed pet food ingredients, which are usually proteins. Each new ingredient is usually offered for up to 14 days (2 weeks) while closely monitoring your pet for any reaction.

What types of diets are used in pet food trials?

1. Novel Diet - This diet has protein component(s) or ingredients that your pet has not eaten in the past. To help ensure a successful outcome, you should have an accurate dietary history of your pet. Protein sources that are usually incorporated in a novel diet include rabbit, kangaroo, venison, pork, or fish. Recommended carbohydrate ingredients include white potato or sweet potato.

2. Hydrolyzed Diet - The protein component of this type of diet has been hydrolyzed or broken down by enzymes, making it so small that it can’t stimulate the immune system. Hydrolyzed proteins commonly used in pet foods include chicken, soy, or feather protein.

3. Homemade Diet - A homemade diet should be balanced and complete, thus you should consult your vet or a pet nutritionist for the right formulation.

There are commercial diets that are labeled “hypoallergenic” or “for sensitive skin”. Take note, however, that these claims are not officially validated and can be greatly misleading.

How a Pet Food Trial is Performed

The initial phase of a food trial involves strictly placing your pet on a trial diet for up to 12 weeks. When switching your pet to a new diet, make sure to observe a transition period to avoid digestive upsets. Changing your pet’s current diet to the trial diet should be done gradually over a 7-day period.

Day 1 and Day 2: 75% of the old diet and 25% of the new diet

Day 3 and Day 4: 50% of the old diet and 50% of the new diet

Day 5 and Day 6: 25% of the old diet and 75% of the new diet

Day 7 and beyond: 100% of the new diet

Tips for Performing a Successful Food Trial for Your Pet

During the trial, your pet must not have access to any other type of food. This includes commercial treats, vitamin supplements, snacks, chew toys, and table scraps. Even toothpaste is not allowed. If your pet is taking oral medications, your vet may prescribe another medication that can be given topically or as an injection. There are, however, healthy treats that can be allowed during the food trial duration. Slices of carrots, apples, broccoli, etc. can be acceptable but make sure to consult with your vet before offering any of these healthy treats to your pet.

Avoid disguising oral medications using sausages, breed, cheese, etc. You can make meatballs from your pet’s canned food or use sweet potatoes to mask any medication that is given to your pet.

If there are other pets in the household, make sure that your pet is not eating other pets’ food or engaging in coprophagy (eating feces). Feed your pets separately or keep a close eye on them during mealtimes. Any bag of pet food should be kept out of your pet’s reach. If you are free-feeding your pets, you should stop the practice to control access to food any time they please.

Pets on a food trial should be strictly confined indoors or monitored very closely when outside to prevent hunting or scavenging.

Make sure that there is enough of the trial food to last the entire trial period. Breaks during the duration of the food trial, even for just a day, should be avoided for proper interpretation of results.

Contact your vet if your pet exhibits digestive upset, such as vomiting or diarrhea, refuses to eat the new diet, does not have any bowel movement for more than 3 days, or appears to be losing weight.

Make sure that everybody in the household understands and follows these guidelines.

Read more:

Allergy Tests for Dogs

Allergy Tests for Cats

Choosing the Right Prescription Diet for Your Dog

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