Grain-Free Pet Foods: Fact and Fiction

cat eating

There are a lot of grain-free pet foods on the market today. People think that grain free means allergy free and better nutrition for their dog or cat. Neither is actually true. Contrary to popular belief, grain-free diets do not offer any health benefits over a diet that contains grains. While some of these foods may be perfectly fine for your pet, current research is finding that grain-free foods made with human-grade ingredients are lacking some key nutrients for the health of your pet.

Let’s start by talking about those “evil” grains. Designer pet food companies want you to believe that corn and wheat are bad for your pet, contain no nutrition, and are just put in foods as cheap filler. This is not true. Grains—corn, wheat, oats, and rice—are excellent sources of essential fatty acids, vitamins, minerals, and fiber.

Corn, when ground very fine, is highly digestible. Grains decrease the total fat and calories in a diet, which is important since over 50 percent of dogs and cats are overweight or obese. Instead of grains, these boutique diets often substitute potato, which has less protein and more sugars. Grain-free foods, as a whole, contain substantially more calories per cup than do non-grain-free foods.

What about the gluten in grains? There’s a rare genetic disease in one line of Irish setters in the United Kingdom with a gluten sensitivity. Apart from that, dogs and cats don’t have documented gluten allergies. Wheat gluten is more than 80 percent protein, with a similar amino acid profile to meats, and is highly digestible. If you see a pet food labeled gluten free, you can be assured it is a marketing gimmick and is not a better diet to feed your pet.

What about food allergies? Food sensitivities (an abnormal response to something in the food that does not involve the immune system, such as lactose intolerance) and allergies (a reaction, like hives or scratching, to something in the food, usually a protein, that involves the immune system) do occur in cats and dogs.

Food allergies are most commonly to proteins: beef, chicken, wheat, dairy, lamb, and corn. Because it takes time (upwards of years) for a food allergy to appear, a pet can develop an allergy to any of the ingredients in a food. If your pet is gassy, has soft poop, or vomits frequently, it might be worthwhile to try a different diet that has a completely different protein source than what you’re currently feeding them.

Photograph provided by Dane County Humane Society

Many of the designer pet foods, however, have a lot of different protein sources, making it difficult to find a food with ingredients the pet hasn’t eaten before. Over-the-counter diets are also manufactured on equipment that makes other pet foods, so there are trace (or more) amounts of different ingredients in the food. Pet food manufacturers can also substitute ingredients in their foods without informing consumers or noting it on the label for up to six months.

“Premium” foods also have a lot of different ingredients, such as flaxseed, vegetables, and fruit, which can cause excessive gas. If you’re concerned your pet may have a food allergy, it is best to work with your veterinarian to find an appropriate food to try.

Recently, the U.S. Food and Drug Administration (FDA) started investigating the connection between dilated cardiomyopathy (DCM) and pet foods containing peas, lentils, legumes, and potatoes as main ingredients (a main ingredient is considered any ingredient before the vitamins and minerals listed on the ingredient list). DCM is a condition wherein the muscles in the heart become thinner, making it harder for the heart to pump. The heart valves may start to leak, eventually leading to congestive heart failure. The disease is thought to have a genetic component and is mainly seen in giant-breed dogs, such as Great Danes, Saint Bernards, Newfoundlands, Irish wolfhounds, as well as boxers, Doberman pinschers, and cocker spaniels.

But recently, several cases of DCM have been diagnosed in golden retrievers, Labrador retrievers, and other atypical dog breeds. In looking into the possible cause, it was found that all the dogs ate grain-free foods as their primary source of nutrition for months to years. Some of the dogs had low taurine levels, an amino acid required for normal heart function. Research is ongoing in this area, but current recommendations by the FDA are to not feed grain-free food.

Boutique pet foods might advertise that they use human-grade ingredients and no by-products. By-products are what is left over once the intended product (often a food made for human consumption) is made. When flour is milled from wheat, for example, the leftover product is wheat bran, which is considered a by-product. Meat and chicken by-products include some parts that people eat (liver, kidney, and tripe) and parts we don’t typically eat (lungs, spleen, kidneys, gizzards, and heart). It does not include hair, horns, teeth, or hooves. If your dog or cat catches an animal in the yard, the first thing they eat are the internal organs. They instinctively know that the highest level of nutrients are in the liver and heart.

If grain-free diets aren’t that great, is a raw food diet a better choice to feed your pet? No! Raw meat can be contaminated with bacteria, such as Salmonella, E. coli, Campylobacter, and Listeria. These bacteria can cause very serious diseases in your pet, which can lead to death. The humans in the house are also at risk from the handling of the food, the food bowl, and from the pet’s mouth. Raw diets are often not nutritionally balanced, which can cause additional health problems in your pet.

Photograph provided by Dane County Humane Society

Proponents of raw diets argue that raw meat and bones are what our pets’ ancestors ate, and they were healthy, had good coats, and nice teeth. But our pets’ ancestors lived, on average, 2 to 3 years, while our pets now live upwards of 15-plus years. Feeding a cooked, balanced diet is much safer and healthier for all involved.

So how should you determine what the best diet is for your pet? First, ask your veterinarian, not the sales person at the pet store. Veterinarians have at least four years of veterinary education and access to the most current research articles on nutrition. Your veterinarian should be discussing your pet’s diet and weight with you at all wellness visits. If they aren’t, speak up and ask!

Spend time looking at the pet-food bag. Remember that besides factual information, the label is a promotional tool to attract pet owners. Unregulated terms, such as holistic, gourmet, premium, all natural, and human grade, are of no value in assessing the nutrition of the food. It’s all advertising and you’re paying a premium for that.

Look at the AAFCO (Association of American Feed Control Officials) information on the side of the bag. If it says “for all life stages,” it’s formulated for growing puppies or kittens and has higher levels of nutrients (and often calories) than a healthy adult animal needs.

Contact the manufacturer to find out if the company employs a full-time veterinary nutritionist who is board certified by the College of Veterinary Nutrition. Companies like Royal Canin, Hill’s, and Purina all have veterinary nutritionists and do research on prescription diets as well as over-the-counter foods. These companies are paying for nutrition research and not just marketing research.

A colorful bag with cute pictures, a high price point, or a heart-rending television ad doesn’t mean a food is any good, let alone the best. The best food is different for every pet—it should be the one with the nutrition research to back up the claims, the one that keeps the pet at an ideal weight with a good fur coat, the one that doesn’t cause a lot of gas, and the one that the pet will eat.

Photograph by Brenda Eckhardt

Lori Scarlett, DVM, is the owner and veterinarian at Four Lakes Veterinary Clinic. For more information, visit fourlakesvet.com .