Truths About Grain Allergies in Pets

I have written several articles about the concerns surrounding grain- and gluten-free diets in pets. While I thought this fad was fading away, there has been new scuttlebutt floating around the internet suggesting there is now proof of gluten allergies in dogs. Because of this, we are once again receiving calls asking whether this is true. The short answer is: not really.

While dogs and cats can have food allergies, grains are very rarely the problem. In pets, food allergies usually involve proteins, not carbohydrates. That means beef, chicken, dairy, eggs, or fish are far more likely to cause itching or digestive issues than rice or corn.

The reason for the renewed gossip on this subject is one rare exception: a gluten sensitivity described in Border Terriers. However, outside of that specific breed, true gluten intolerance in pets is extremely uncommon. Unlike people, pets almost never have a medical condition similar to celiac disease, where gluten triggers an autoimmune reaction. So while humans may need to skip the bread basket, most dogs and cats can eat grains without any issue at all.

So why do so many pets seem to “do better” on grain-free diets? This is where things get a little tricky. When a pet switches foods, many things change at once—not just the grains. Grain-free diets often rely on different proteins, fat sources, and ingredient combinations due to the removal of grains and their associated nutrients. If a dog was allergic to chicken and switches to a grain-free food that happens to use lamb or salmon instead, they may improve—but not because the grain disappeared.

Food allergies in pets typically show up as ongoing digestive upset or itchy skin, not dramatic reactions like swelling or trouble breathing. That’s why diagnosing food allergies requires patience and a proper elimination diet, rather than guessing based on an ingredient list.

Grain-free diets also aren’t automatically “healthier.” In many cases, they can even be risky. You may have read my past articles about certain grain-free diets being linked to serious heart disease. This connection remains strong enough that veterinarians continue to recommend avoiding grain-free diets unless there is a clear medical reason to use one. Grains like rice, oats, and barley are not “fillers”—they provide energy, fiber, and important nutrients, and most pets digest them very well.

The bottom line? Most dogs and cats do not need to eat like gluten-free humans. If your pet is experiencing digestive problems, the answer is usually not removing grains—it’s finding the right diet for that individual pet. And that’s a job best done with your veterinarian, not the marketing team at a pet food company.