What is a Food Allergy?
Most people know of friends or family members who have a food allergy such as peanuts, dairy and gluten. Dogs and cats can get food allergies as well. A food allergy is caused by the inappropriate response of an animal’s immune system to something it eats. The most common signs of food allergies in pets are itchy, red skin and ears and gastrointestinal upset such as vomiting and diarrhea.
The most common food allergens for pets are protein sources such as chicken and beef. These allergies develop after multiple exposures to the allergen. For this reason food allergies can occur in dogs and cats that have been on the same food for many years and do not need to be facilitated by a change in diet. Despite popular belief, most dogs have no problem tolerating grains such as corn and while cats should generally be fed a diet low in carbohydrates, they are very rarely “allergic” to grains. For this reason, switching your pet to a grain-free diet is not usually a sufficient treatment for food allergies.
How Are Food Allergies Diagnosed?
There are several steps involved in diagnosing food allergies. The first step is for your veterinarian to obtain a thorough history of your pet’s symptoms and diet including all treats and medications he/she takes. A physical exam should also be performed and depending on your pet’s symptoms, your vet may also recommend some tests such as skin scrapings and fecal samples to rule out other diagnoses. While blood tests for food allergies are available, most specialists believe these are currently an inaccurate and ineffective means of diagnosing food allergies and do not recommend them. Once your veterinarian has ruled out other causes of your pet’s symptoms and suspects a food allergy is likely, they will recommend a food trail. This is a period of time where your pet is placed on a special hypoallergenic diet to see if their signs dissipate.
How is a Food Trial Performed?
In order for a food trial to be successful, your pet must be placed on a special hypoallergenic diet. There are several options, both commercially available and homemade, and the best choice of food for your pet will be determined by you and your veterinarian.
A food trial generally takes 8-12 weeks to complete. For this initial food trial it is extremely important that you not allow your dog or cat to be exposed to any food other than the special diet as even miniscule amounts of something your pet is allergic to can cause significant symptoms and invalidate the results of the test.
Below are important rules to follow when performing a food trial.
- When starting a food trial, be sure to thoroughly wash any bowls or containers that stored the previous food.
- Transition your pet’s diet slowly by mixing the new food with the old food over the course of a week.
- If you must feed treats to your pet, ask your veterinarian for treat options that are compatible with the food trial. This may include special prescription treats, or you may use the diet itself as a treat between meal times.
- You may need to feed the special diet to your other pets as well if you can not prevent them from eating each other’s food. If your pets can not share food (ie. They are different species, or your other pet is already on a prescription diet) be sure to keep them separated during meal times.
- Keep your pets out of the kitchen at family meal times, especially if you have young children or other family members who may drop food or share food with your pet.
- You may need to make changes to your pet’s medications, such as monthly heartworm preventatives as many pet medications are made with beef or chicken flavorings that your pet may be allergic to. Non-chewable medications are usually fine, but can not be hidden in other food. Be sure to discuss this with your veterinarian so that your pet’s other medical need are met during the trial.
- Toothpaste and certain toys may also have flavorings added so be sure to avoid these during the trial.
- Keep your pet monitored and leashed if necessary when outside if they have a tendency to pick things up off the ground.
If you have any questions or concerns
about your or your pet’s ability to follow a food trial, please discuss them with your veterinarian so that they may help you help your pet. Once the food trial is over, some of these guidelines may be able to be loosened depending on the severity and cause of your pet’s allergy, but again, be sure to discuss it with your vet as any additions to your pet’s diet will need to be done in a controlled manner. And remember that it may take a couple of months to see improvement with the trial, so don’t give up!