Pet owners want Fido and Fluffy to have most nutritious ingredients possible without any “extras” or “fillers.” That doesn’t necessarily square with science.

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On Nutrition

Do you have pets? If so, odds are good that you consider them part of the family — and may be tempted to feed them like people. Pet-food-industry trend experts are forecasting that pet owners will increasingly demand the same qualities in pet food that they want in their own meals, narrowing the gap between pet food and human food. What’s falling out of favor are scientific or lab-based pet-food formulations, because they don’t feel “human.” Pet owners want Fido and Fluffy to have most nutritious ingredients possible without any “extras” or “fillers.”

Unfortunately, grains are perceived as one of those fillers. There’s a certain logic to not including grains in dog food — dogs are carnivores, after all. However, whole grains do provide nutrients and have been safely used in pet foods for a long time. Nevertheless, between 2012 and 2016, grain-free and gluten-free pet foods increased their market share from 7 to 19 percent, the largest shift in any pet-food category. This may be having some devastating consequences.

Last year, the breeder of my now 17-month-old golden retriever stopped recommending a certain brand of high-end dog food because of its connection to some disturbing reports. The veterinary school at the University of California, Davis, had starting seeing more dogs, including golden retrievers, with canine dilated cardiomyopathy (DCM), accompanied by deficiencies of the amino acid taurine. Canine DCM affects the heart muscle, resulting in an enlarged heart. This makes it harder for the heart to pump, so heart valves may leak, leading to a buildup of fluids in the chest and abdomen. This often results in congestive heart failure.

What’s unusual is that many of these cases were in dog breeds that are not typically genetically predisposed to DCM. They were also more likely to be eating small-batch boutique, grain-free or exotic ingredient diets. The situation is serious enough that the Food and Drug Administration (FDA) is involved. In cases reported to the FDA, the food brands the dogs were eating frequently listed potatoes or multiple legumes such as peas, lentils, and beans — or their isolated protein, starch and fiber — early in the ingredient list, which indicates that they are main ingredients.

Large amounts of legumes or potatoes appear to be more common in pet foods labeled as “grain-free,” but it is unclear how these ingredients are linked to cases of DCM. The brand our breeder stopped recommending — which markets itself as selling natural, grain-free “biologically appropriate” pet food with “fresh, regional ingredients” — does list animal protein as the first few ingredients in its products. However, that’s followed by a long list of legumes: whole red lentils, whole pinto beans, whole green peas, whole green lentils, whole chickpeas and lentil fiber.

It may be that grain-free formulas and/or legume-based diets are causing taurine deficiency-related DCM, either because they lack an adequate amount of taurine in their formula or the legumes interfere with a dog’s ability to produce or absorb taurine. Golden retrievers might have something in their genetic makeup that makes them less efficient at making taurine, so this type of diet could effectively be a double hit.

The good news is that in dogs with DCM due to taurine deficiency, taurine supplementation often restores heart function, if the condition is caught early. The recommendation is that if you are feeding your dog a food heavy in legumes, talk to your vet about a blood taurine test before making a dietary change. If the blood results indicate taurine is low, an echocardiogram may be needed.