Food allergies are one of the irritating (itchy) and lifelong conditions of small animals. Our pets eat a variety of processed proteins, flavourings, and colourings. These substances are recognized by the immune system of allergy prone pets as foreign objects. The immune system responds to these foreign objects by attacking them and causing inflammation. The resulting inflammation usually targets the gastrointestinal (GI) tract and skin in dogs and cats. Dogs with food allergies can be itchy around their face, anal area, and usually bite or chew at their foot or limbs and be susceptible to recurrent ear infections. Cats may have scabs and other signs of itching around their face or neck. Many people mistakenly assume allergic reaction are to food or sudden introduction of a new diet when the opposite is true. Food allergies require time to develop; most animals have been eating the offending food for months with no trouble.
Pets can have either food or environmental allergies, or in some cases they can have both. In fact most allergic pets, they have multiple allergies adding together to make them itchy. It is difficult to differentiate food allergy from environmental allergy because there is no simple test for food allergy, and allergy tests are not useful for diagnosing food allergy.
Then how can food allergy be diagnosed? The Hypoallergenic Diet Trial.
To determine whether or not a pet is suffering from food allergy a hypoallergenic diet needs to be fed for at least 2-3 months. If the pets clinical signs resolved during this time period, the original diet is fed for up to two weeks to see if itching reoccurs. If we see recovery with the hypoallergenic diet and itch with the original diet, then food allergy is diagnosed and the pet is returned to either the hypoallergenic diet or another appropriate food indefinitely. It is important to ensure the diet is strict during the trial, which means the pet should have no access to any other protein sources other than what is being fed in the hypoallergenic diet. This includes rawhides , bones, treats, chews, flavored chewable medications and supplements. If a food trial under supervision of a veterinarian is unsuccessful, environmental allergy are suspected.
What is a Good Hypoallergenic Diet?
There are two categories of hypoallergenic diets: novel protein and hydrolyzed protein. A novel protein diet is a diet with a single protein source that the patient has never eaten before. Novel proteins include venison, Bison, fish, duck, crocodile, rabbit and even kangaroo. Recently, several diets that include duck and venison have been released to the general market.
Several pet food companies have released single protein diets for over-the-counter sales. While these diets may seem like a novel protein diet, they are not a good choice for a diet trial because these diets contain additional proteins (probable contaminants from prior batches in the pet food factory). These impurities can lead to false results in a diet trial. It is recommended that a therapeutic diet under the supervision of your veterinarian be chosen. Therapeutic diets go through extensive wash out periods before production and are being tested for contaminants before releasing them to the market. The other benefit to therapeutic diets is that they have a 100 percent guarantee. This means that if your pet doesn’t like the food, the food can be returned for a complete refund, even if the bag is opened. This is especially helpful for picky pets.
The second kind of hypoallergenic diet is hydrolyzed protein diet. In hydrolyzed protein diets, a conventional protein source is used but the protein is broken down into molecules too small to mount an immune system response.
Home cooking or raw fed diet are good alternatives to therapeutic hypoallergenic diet for the diet trial. Home cooking can be inconvenient but for the right owner, it is a good choice. Recipes for appropriate diets can be purchased and found through BalanceIt.com, petdiets.com , and Hillary’s blend book. Alternatively, you can consult your veterinarian for home-cooked recipes.
If you think your pet struggles with food and/or environmental allergies, please contact us at Legacy Veterinary Clinic (587-625-0748) to discuss options for your pet. We are here to help you give your pet the best quality of life possible.