A food allergy is present when a dog or cat has an allergic hypersensitivity reaction to a product contained in a diet. These allergic reactions can be due to protein sources which may include beef, poultry, pork, fish, eggs, or soybeans. Sometimes the pet may be allergic to the carbohydrate source, which may include wheat, corn or rice. Additives, colorings, flavorings and preservatives may also be to blame.

Symptoms of a food allergy

The two major syndromes of a food allergy are skin allergies with unrelenting scratching and gastrointestinal problems accompanied by vomiting and diarrhea.

Skin Allergies

Pets with skin problems have year-round scratching, which is not resolved by bathing or using antihistamines or steroids. Different areas of the body can be involved including the ears, paws, inguinal and axillary region, the forelegs and face. In some dogs and cats, the only area affected by the food allergy are the ears.

Gastrointestinal Allergies

Pets with gastrointestinal food allergies have symptoms of vomiting, diarrhea or both. Initially the episodes of vomiting or diarrhea may be intermittent but eventually they occur daily in association with feeding.

Diagnosis of a Food Allergy

There is no reliable blood test or skin test for diagnosing a food allergy. A food trial is the only alternative. The diagnosis of a food allergy is established by feeding the patient a hypoallergenic diet consisting of a novel protein, (a protein never fed before) and carbohydrate diet for the next 4-8 weeks and observing the patient for improvement. During the initial testing period, no other foods, treats, or supplements should be fed. Once a pet develops a food allergy, the allergy is present for its entire life.

Hypoallergenic/Food Allergy Diets

There are several diets available for dogs and cats in both dry and canned presentations. These are balanced diets, which can be fed for the entire life of your pet.


Royal Canin Diets
Venison and Potato
– comes in 13oz. cans
-comes in 7, 17 and 25lb bags

Duck and Potato
-comes in 13oz. cans
-comes in 7, 17 and 25lb bags

Rabbit and Potato
-comes in 13oz. Cans
-comes in 7, 17, and 25lb bags

Hill’s Prescription Diets
D/D Duck and Rice, D/D Egg and Rice,
D/D Salmon and Rice
-comes in 14oz cans
-comes in 10lb and 20lb bags

Z/D Ultra Allergen-Free
-comes in 14oz.and 5.5oz cans
-comes in 10lb and 20lb bags.


Royal Canin Diets
Venison and Pea, Duck and Pea, Rabbit and Pea
– comes in 5.5 oz cans
– comes in 8lb bags

Hill’s Prescription Diets
D/D Venison and Pea, Duck and Pea
– comes in 3.5 and 8.5lb bags
– comes in 5.5oz. Cans

Z/D Ultra Allergen-Free
– comes in 4 and 8lb. Bags
– comes in 5.5oz. cans

Some Important Facts About Food Allergies:

– A change from one commercial pet food to another commercial pet food will not improve a food allergy. All commercial pet foods have similar ingredients used to formulate the diet and the only difference between them (from an allergy standpoint) is the price and the color of the packaging.

– A dog or cat can develop a food allergy at any age.

– A dog or cat can develop a food allergy to a diet that it has eaten its entire life.

– Only the hypoallergenic diet can be fed to a dog with a food allergy. Table scraps, dog treats, chewable treats (cow hooves, or pig ears), vitamin and mineral supplements or even monthly heartworm medication can be responsible for a continuation of the food allergies even when the hypoallergenic diet is fed.

– The goal of the food trial is to see if the pet’s symptoms subside while being fed the hypoallergenic diet.