Itchy skin, diarrhea, refusing to eat his food — if your dog or cat displays these symptoms on a regular basis, you may have a food allergy on your hands. If you suspect that your pet may be allergic to a certain ingredient in their food, but can't quite pinpoint the culprit, there are several ways to test for food allergies, both with the help of your veterinarian and from the comfort of your own home.
Food allergies can make eating a nightmare for your pet. According to Cummings Veterinary Center at Tufts University, an allergic reaction to food takes place when your dog or cat's body mistakes protein for something harmful, like bacteria, and alerts their immune system to respond as if it needs to attack it. This reaction often leads to symptoms ranging from skin irritation to digestive issues, like diarrhea. Regardless of the symptoms, it's safe to say that allergies are uncomfortable, at best, and ultimately, avoidable, assuming you know the right things to test and keep and eye out for.
How to test
If you think your pet may have a food allergy, there are measures you can take to find out which proteins are causing the damage. To test your pet for allergies with the help of a veterinarian, your pet will require that a sample of tissue from their skin or a sample of blood be taken from them. To take a sample from the skin, which is known as an intradermal allergy test, or IDAT, Vet Allergy explains that your pet will be given a mild sedative before being given several light doses of injections of common allergens to the skin. If any of the injection sites show a reaction, this can indicate the allergen. Due to the inefficacy of some of these types of tests when it comes to food ingredients, however, some veterinarians will not conduct skin or blood tests for food allergies and limit testing only to environmental allergens.
If you need to test your pet for food allergies, you can look to online options if your veterinarian thinks the aforementioned method won't produce affirmative results. Sites like Affordable Allergy Testing use hair samples to test for food and environmental allergies and produce results within 7 days. The breakdown of your pet's test is then displayed using a color-coded and numbered system to help pet owners understand which allergens are most likely to cause harmful symptoms, like skin or digestive issues. The test goes on to highlight any metals or minerals in your pet's food that may be contributing to your pet's symptoms, along with potential nutritional deficiencies, like low protein intake or a vitamin imbalance.
If you're on the fence about having your dog undergo a formal allergy test, you can test them for food allergies using something called an elimination diet, says DVM 360, which is a method recommended by most medical sources. To do this, you'll need to select a formula of food that contains proteins your pet has not previously been exposed to. For example, if your pet usually eats beef formula, try finding a formula which features lamb or fish as the main protein source. Finding a formula containing hydrolyzed protein has also shown to be an ideal option for an elimination diet. Next, feed your pet only this food — that means no treats, no table scraps, no vitamins or supplements, and no other dog food. If you live in an interspecies home and your canine tends to sneak over to the cat's bowl, keep your feline's food in a place your dog cannot reach to ensure the best results.
Finally, keep your dog or cat on this restricted diet for several weeks, and make note of any changes to his symptoms and behaviors. If your pet's symptoms have cleared up, you have likely identified that the protein source contained within his former food which was responsible for his allergies, and should discontinue feeding him that ingredient. If no improvement has been made, keep trying with other formulas until your pet shows signs of eliminated symptoms. This is a lengthy process of elimination but has been shown to be one of the more effective methods for identifying possible allergy sources in pet food.
Other causes of allergy-like symptoms
Before jumping to the conclusion that it is a food allergy that's causing your pet to itch or have gastrointestinal issues, it's important to rule out other possible allergens. While some pets are, in fact, allergic to certain food ingredients, many allergies are caused by environmental factors unrelated to their diet, like dust mites, fleas, or bacterial infections, to name a few. Before you begin your food allergy testing journey, it's best to consult your veterinarian to rule out any possible reasons for your dog or cat's allergies, and to receive guidance regarding the best way to test for food allergies if that is the case.