Grain-free pet foods are no healthier, vets say.

These grain-free, all-meat and raw-food diets are inspired by the meals eaten by wild relatives of our fidos and felixes. But are these diets really better for our pets? Veterinarians and pet nutrition researchers say probably not.According to clinical veterinary nutritionists at Tufts University, grain-free foods were one of the fastest-growing sectors of the pet food market in 2016. “All I ever hear is, oh, on a good diet, it’s grain free,” said Dena Lock, a veterinarian in Texas. The majority of her pet patients are overweight. “Grain-free is marketing. It’s only marketing,” said Cailin Heinze, a small-animal nutritionist at Tufts University’s Cummings School of Veterinary Medicine. “A lot of foods market themselves by what they’re not including,” and the implication is that the excluded ingredient must be bad. Some pet owners have a false impression that grains are more likely to cause an allergic reaction, but “it’s much more common for dogs to have allergies to meat than to grain,” Heinze said. Chicken, beef, eggs, dairy and wheat are the most common allergies in dogs. And it’s not that there’s anything particularly allergenic about these foods, she said, they’re just the most frequently used ingredients.