Are Grain-Free Pet Foods Superior?

Focus On Maintaining Healthy Body Weight.

The current trend of feeding pets grain-free diets is inspired by the meals eaten by wild relatives of our fidos and felixes and is driven by intense marketing and television advertising campaigns.

But are these diets really better for our pets? Veterinarians and pet nutrition researchers say probably not. Board certified clinical veterinary nutritionists at Tufts University Veterinary School confirm that grain-free foods were one of the fastest-growing sectors of the pet food market in 2016. Every day at PSVC, when I ask what an owner feeds their dog, the response is often, “oh, he’s on a good diet, it’s grain free”. The majority of these patients are overweight.

Why have these pet diets become so popular? “Grain-free is marketing. It’s only marketing,” states Cailin Heinze, a small-animal nutritionist at Tufts University’s School of Veterinary Medicine. ” A lot of foods market themselves by what they’re not including,” and the implication is that the excluded ingredients must be bad.

“Grain-free is definitely a marketing technique that has been very successful,” said Jennifer Larsen, a clinical nutritionist at the University of California Veterinary School in Davis. People think that if they pay a lot for food and there are a lot of ingredient exclusions on the bag, that the food is healthier, but “they’re buying an idea,” she said, “not necessarily a superior product supported by science.”

Here’s the real surprise that I don’t think most of our PSVC clients realize. If you look at the label of your grain free food, it is not carbohydrate free. They just replace the grain carbohydrates with starch carbs like potato starch, pea or lentil flour, and tapioca starch, among others.

Since these foods contain carbs in another form, there is absolutely no data to support the idea that grain-free diets are better for pets, Heinze and Larsen noted.

Some pet owners have a false impression that grains are more likely to cause an allergic reaction, but “it’s infinity more common for dogs to have allergies to meat than to grain,” Heinze said. Chicken, beef, eggs, dairy and wheat are the most common food allergies in dogs. And it’s not that there’s anything particularly allergenic about these foods, they’re just the most frequently used ingredients. If an animal is genetically prone to developing allergies, the more exposure to these, or any other proteins, at an early age, the more likely food hypersensitivities are to occur. However, food allergies are much less common in dogs and cats than environmental allergies.

Marketing campaigns for products such as “Taste of the Wild” or Blue Buffalo’s “Wilderness” claim that their grain-free, meat/fat-forward formulations better reflect the ancestral diets of our dogs’ and cats’ evolutionary predecessors, but these veterinary nutrition specialist veterinarians also question this logic.

For one, our pets’ wild cousins aren’t all that healthy. “People believe that nature is best,” Larsen said, but “animals in the wild don’t live that long and they don’t lead very healthy lives.”

For dogs, we know that they have diverged from wolves genetically in their ability to digest starches. “Dogs aren’t wolves,” said Robert Wayne, a canine geneticist at UCLA. “They have adapted to a human diet.” Wayne’s research showed that most wolves carry two copies of a gene involved in starch digestion, while dogs have between 3 and 29 copies. According to Heinze, the average dog can easily handle 50 percent of its diet as carbs. If you cut grains, add other starches, increase protein, and especially fat calories, your dog is going to gain weight.

For cats, this argument makes a little more sense. Cats are carnivores rather than omnivores, so they have higher protein, and, especially, fat requirements than dogs, but “cats can actually digest and utilize carbohydrates quite well,” said Andrea Fascetti, a veterinary nutritionist at the University of California Veterinary School in Davis.

Another key point is that dogs and cats also have a drastically different lifestyle from wolves or tigers. Today pets are almost always housed indoors or in pens with decreased daily activity, so their energy needs are reduced dramatically. This is in itself a risk factor for obesity. Many of these super premium grain free dog foods are formulated to be fed at the rate of one cup per 25 to thirty pounds per day, depending on activity level, ie. working dog on a farm versus dog on the couch for your 10 hour work day.

There’s no one magic diet for every animal. When it comes to navigating marketing claims in the pet food aisle, I would suggest finding a company that consults with, or employs a veterinary nutrition specialist and does feeding trials on large numbers of various breeds of dogs. Try not to get too hung up on “the no list”.

Studies have found that feeding dogs and cats to maintain a lean body weight has very positive effects on their overall health and can even increase the span of their best quality of life. Please talk with our Doctors about any dietary questions you might have.


Pittsburgh Spay & Vaccination Clinic is a state-of-the-art, full-service suburban veterinary facility serving the Pittsburgh Area since 1980.. We offer diagnostic, medical, surgical, and dental care to dogs, cats, ferrets, rabbits, and pocket pets in the Pittsburgh area.

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