Feline Food Allergy Elimination Diet Procedures

An elimination diet is used to test for food allergies. This article explains what food allergies are, and how elimination diets work.

Ingredients May Cause Food Allergy

A food allergy is an overreaction of your cat’s immune system to one or more ingredients in the food. The most common allergy-causing ingredients in cat food are beef, lamb, corn, soy, dairy products, fish and wheat gluten. Preservatives, coloring and fillers have also been implicated in feline food allergies.

Food allergies can occur at any time in your cat’s life, with most cats showing signs between the ages of 2 and 6 years. Your cat can develop food allergies after eating a diet that contains the allergen for more than two years.

The most common clinical sign of food allergy in cats is itching. Your cat will scratch her belly, face, feet and ears. Other signs include hair loss, frequent scratching and skin irritation. Secondary skin infections may result from the skin irritation and scratching.

Elimination Diets Help Make a Diagnosis

An elimination diet is designed to test a cat for food allergies by offering protein and carbohydrate sources your cat has never eaten before. New protein sources may include duck or venison, and new carbohydrate sources may include potato or sweet potato. The cat must eat only the elimination diet for about three months to determine whether she has a food allergy.

Over time, the allergy-causing ingredients your cat has consumed will be eliminated from her body, and her itching should decrease. At this point, your veterinarian may recommend re-introducing one or more ingredients from her old diet to confirm the diagnosis.

Elimination diets are the best way to diagnose a food allergy in your cat since laboratory tests are not as accurate in making a diagnosis.

How Elimination Diets Work

Elimination diets work by removing one or more allergy-causing ingredients from a cat’s diet. Through a process of elimination, your veterinarian can determine what allergens cause your cat’s clinical signs, and a new diet can be created that won’t cause problems for your cat.

Feed the Elimination Diet as Instructed

Your veterinarian should be able to determine whether your cat has a food allergy after she has been on the elimination diet for about 12 weeks. As noted earlier, your cat should eat only the elimination diet during this time without the addition of treats or snacks.

What to Feed After the Allergy Is Confirmed

In many cases, cat owners opt to feed the elimination diet as the cat’s new diet once a food allergy has been confirmed.
Another relatively new therapy for food-allergic cats is to eat a hydrolyzed protein diet. These diets feature proteins and carbohydrates that are broken down into tiny molecules that cannot cause an allergic reaction, even in sensitive pets.