How do I know if my pet is allergic to her food? Symptoms can include general or localized inflammation, skin problems, itchy paws, yeast accumulation in the ears, vomiting, diarrhea, and mouth ulcers.
Keep in mind that all of these symptoms can be indicative of health issues other than food allergies. What are common food allergens? A survey of vets suggested the most common culprits as preservatives and dyes, wheat, beef, corn, soy, chicken egg, dairy, and lamb. However, this list changes over time, as the use of common food ingredients tends to run in cycles. This is because repeatedly ingesting a singular protein may cause an overload on the body’s mucosal barrier. So, while lamb and rice were once viewed as being useful for allergy-prone dogs, now so many dog foods contains lamb and/or rice that now more animals are developing allergies to one or both ingredients.Are some breeds more likely to have allergies? Some research suggest yes, while others can’t find any proof. Studies that have found a correlation note that it’s a long list, including spaniels, terriers, labs, German shepherds, Lhasa Apsos, dachshunds, golden retrievers, and so on. Cats tend to be more sensitive to foods than dogs, especially fish.What about diagnosis and treatment? Allergy tests in companion animals are more accurate for environmental triggers than they are for foods. In fact, there is no reliable test to determine the specific cause of a pet food allergy. Normally the solution to a suspected food allergy would be to start an elimination diet, in which the animal is fed a food containing one meat protein and one starch, such as salmon and sweet potato or kangaroo and lentil. If the pet has a reaction to one two-ingredient formula, another is tried, and so on.Keep in mind there is no such thing as a true hypoallergenic diet, only diets that contain ingredients that are less likely to cause reactions. In rare cases an animal may need a food in which the proteins have been hydrolyzed, that is, processed so the protein is broken down to make it less likely to trigger an immune response.
What can I do to help prevent the occurrence of a food allergy? You can help your pet digest protein so completely that harmful particles can’t antagonize the mucosal barrier in your dog’s or cat’s intestine. One way to do that, and help overall digestion, is to encourage them to drink water at mealtime. If you feed your pet dry food, add water to it—don’t worry about reducing the dental benefit from eating kibble, since it’s negligible.Also, use a cat or dog food that has a variety of protein sources, or if using a single-meat protein food, rotate to other varieties if possible. Changing food ingredients not only reduces the change of an allergy from forming, but it strengthens the immune system. Here’s a quote from a widely used clinical text: “Dogs and cats may develop food allergy after prolonged exposure to one brand, type, or form of food.”
Some pet food manufacturers used to recommend keeping your pet on one type of food, but until the last twenty years or so, most of them manufactured only one formula. Coincidence?
Besides me, who is my pet’s best friend?
Bacteria. The use of prebiotics and probiotics can not only help digestion, but can strengthen the immune system. So, while they won’t actually “cure” an allergy, they can help prevent one, or help calm the symptoms. In the case of non-allergy adverse reactions, they can eliminate the digestive problem altogether.
Which is easier to get rid of: an allergy or a relative?
An allergy. In research involving humans, strictly avoiding a food allergen for a number of years may allow the individual to consume the food later in life with no adverse effects. Animal and human immune systems are very similar in that regard.
I read on the internet that corn is horrible because it causes allergies and is used as a filler, and is basically Satan’s favorite food. Is that true?
Not quite. It’s true that in the pet food world, corn is as welcome as a yellow jacket at a barbecue, but there’s more to the story.
Like any other protein, corn can trigger an allergic reaction. The problem with corn or any other single substance is that it it’s used too often in too big a dose, it increases the odds that an animal will develop an abnormal immunologic response. It’s not corn’s fault—if a dog was fed high daily doses of duck, lentils, potatoes, broccoli, or any other ingredient, they could develop an allergy to it as well.
On the other hand, corn was, and in some cases still, used as a primary ingredient in many middle and lower market brands. If whole grain corn was, say, the tenth item on an ingredient panel, I wouldn’t have a problem with it, since it does add fiber and other nutrients. However, far too often corn-based ingredients are used because until recently, it’s been cheap. However, a few of the well-known brands that have traditionally used high levels of corn products have been able to obtain high prices for their food, in great part because of effective marketing strategies.
Want more information?
Many food manufacturers have excellent research available online. Some examples:
 By Sally Perea, DVM, MS, DACVN, Senior Nutritionist and Nathan Fastinger, PhD, Senior Nutritionist, Natura Foods, Technical Information Series, Vol. 4, # 1.Found at www.naturapet.com
 For helpful information about pet dental care, see the website for the American Veterinary Dental Association: http://www.avdc.org/carefordogs.html
 Hand, Thatcher, Remillard, and Roudebush, Small Animal Clinical Nutrition, 4th Edition(Topeka: Mark Morris Institute, 2000), Chapter 14. This book was produced by Hill’s Pet Nutrition, the maker of ScienceDiet and Prescription Diet. While Hill’s conducts excellent research, sometimes it seems the manufacturing and marketing divisions follow different philosophies.
 Prebiotics are in essence, “food” for probiotics (good bacteria).
 Hand, et al, 446. Human and companion animal immune response are similar enough to draw conclusionsfrom each other.
 There are other issues to consider, such as the bioavailability of the protein in corn vs. other ingredients,and the glycemic load, but those are topics for other articles. See the July issue of Northwest Pet for moreinformation
 Corn prices have risen considerably in the past few years, and will continue to rise this year. A few of the large food manufacturers that used to swear corn was a great kibble ingredient are now manufacturing some foods with no corn, and advertising “Corn Free!” It’s odd how prices seem to dictate the nutritional value of an ingredient.