Have you ever cut chicken out of your pet’s diet because you were worried it might be the cause of their recurrent skin and ear issues? Maybe you have tried grain free diets, home-cooked diets, or rotated proteins for the same reason. Food allergies in dogs and cats, while very real, are one of the most misunderstood areas of veterinary dermatology.
Marketing from dog food companies and anecdotal reports from friends or family are often compelling but not an accurate representation of the science of food allergies. Increased availability of specialty and boutique brand dog foods also adds to the perception that there is an increased need for limited ingredient diets due to allergies.
What We Know
Food allergies in dogs and cats can affect their skin, ears, gastrointestinal tract, or all of the above. Out of all the allergic pets we treat in Dermatology, food allergies only account for approximately 20% of cases, while environmental allergies are a much more common cause of skin and ear problems. Some pets may have concurrent food and environmental allergies. Dogs and cats with food allergies affecting their skin can be itchy and develop rashes or infections. They are generally affected year-round and symptoms do not increase or decrease with seasonal changes.
Pets can develop food allergies at any age of life, even spontaneously to a food source that the pet has eaten without issue for many years. Food allergies actually REQUIRE that the pet has consumed the allergen before and had the opportunity to sensitize to it; therefore, they are generally not associated with new diets or diet change. The vast majority of food allergies in our pets are to proteins, such as chicken, beef, fish, pork, dairy, etc. Only rare cases of grain or carbohydrate allergies have been reported. These proteins aren’t inherently bad or more likely to cause allergies than others, they are just the proteins most often fed to our pets, and therefore more likely to become an allergen in a dog prone to developing allergies.
When to suspect a food allergy in your pet
-If your pet develops skin or ears issues (including itch, rashes, or infections) that persist year-round or on a regular schedule (ex: ear infection every 12 weeks)
-Your pet is younger than 1 year or older than 5 years when skin disease starts
-Your pet has concurrent skin and GI issues
Is there a test for food allergies?
Sadly, there is no test that can accurately diagnose a food allergy in our pets. There are many tests on the market that claim to, but scientific studies repeatedly conclude that no testing method is valid for diagnosis of food allergies in pets. The only way to diagnose a food allergy is to perform a strict 8-week elimination diet, generally with a prescription hypoallergenic diet, under the guidance of your veterinarian. Home-cooked diets can be used as well but should be formulated by a veterinary nutritionist to make sure they are complete and balanced. Grain-free diets are generally not recommended, as grain allergies are very rare, and these diets have been associated with a specific type of heart disease in dogs.
The good news is that having a food allergic pet is the best kind of allergic pet to have, since you are (mostly) in control of their diet. You may be somewhat limited in what they can eat, but there are many options appropriate for food allergic pets once you determine the source of the allergy. If you are concerned your pet may be suffering from a food allergy, give us a call! Relief may only be an elimination diet away.