Food Allergy Article

Food Allergies

How can I tell if my pet has food allergies? What are the most common symptoms?
Dogs and cats will most often present with chronic itching which may involve the ears, flank, perineal, or trunk areas with possible secondary bacterial infection. The itching typically does not change from warmer to cooler seasons. In addition to itching, gastrointestinal problems, such as soft stool, flatulence, chronic diarrhea, and vomiting may also be related to food allergies.

Is there an age or sex predisposition to food allergies?
No, food allergy can develop at any time in a pet’s life, from as early as 2-3 months and any time thereafter. There seems to be no predisposition for males or females. Both sexes are equally affected by food allergies.

What is the best way to diagnose food allergies?
There is currently no reliable diagnostic test for food allergies. Diagnosis is usually derived by putting the pet on a food trial which consists of feeding your pet a diet with a novel protein and carbohydrate (one that the pet has not been exposed to in the past), in addition to avoiding any unnecessary exposure to other proteins or carbohydrates.

My pet has been on the same diet for years, how can he be allergic to the diet?
Dogs and cats can develop antibodies against certain proteins as their systems are repeatedly exposed to the same protein and/or carbohydrate over a long period of time. This sometimes leads to an abnormal immune reaction which is described as an allergy. Thus dogs and cats with no change in diet can suddenly develop food allergies to their diets.

What is the best diet to feed my pet if I suspect food allergies?
When deciding on a diet to rule out food allergies, a novel protein, such as venison, fish, rabbit, duck, or eggs should be considered. In addition to a novel protein, novel carbohydrates including potatoes, sweet potatoes, or rice should be considered. These are uncommon protein and carbohydrate sources that few pets have been exposed and hence more likely to be effective. The most common proteins in diets are beef, chicken, and lamb whereas the most common carbohydrates are corn, wheat, and soy. We have seem good results from Royal Canin diets as venison and potatoes, white fish and rice, duck and potatoes, rabbit and potatoes. Hill’s D/D line is also routinely used, which includes eggs and rice, and fish and potatoes. Hill’s also produces a diet specific for extremely allergic dogs called Z/D with a modified protein.

How long should I wait to see if the new diet is working? What else can I feed my pet during the new food trial period?
The new diet has to be fed exclusively for 8-12 weeks to prove efficacy, but you may see results in as little as 2 weeks. During this time, the pet should not eat any other protein or carbohydrate except for the designated diet. During the trial period, do NOT give your pet any other treats, raw hides, pig ears, human foods (cheese, peanut butter, carrots, etc), flavored tooth paste, or flavored medications. Please ask one of our veterinarians about the medications your pet may be currently taking, including heartworm prevention and over the counter supplements. Allowable treats are canned food equal to the recommended dry food. You can make treats from the canned food by cooking it at 350F for 35 minutes. Plastic toys as Kong balls filled with the recommended diet is a great way to keep your pet entertained.

How do I know the food trial is working?
Your pet will need to stay on the same diet for the expected 8-12 weeks. If clinical signs improve or resolve, then a presumptive diagnosis of food allergy is made. Once this is done, the same diet can be fed for the rest of the pet’s life, or if desired, single servings of one ingredient can be re-introduced to test the pet for allergies. If re introduction is performed, monitor your pet for itching, ear and anal gland infections, vomiting, and diarrhea.

Can my pet‘s allergies flare up once in the food trial?
Allergic signs should be minimal to none once your pet is on a successful food trial. However, it is common for pets with food allergies to flare up with seasonal allergies, especially during the spring and summer seasons. This is a frustrating event for the owner, the pet, and the veterinarian, but this should not be confused with a failed food trial.