New Study Flags Alarming Toxic Metal Levels in Commercial Dog Food, Especially Dry Kibble

On average, dry food contained 5.7 times more arsenic, 3.2 times more cadmium, 2.7 times more mercury and 12.7 times more lead than the group’s benchmark for human consumables.

Rudy Blalock

Published: 2/13/2026, 3:59:57 PM EST

New Study Flags Alarming Toxic Metal Levels in Commercial Dog Food, Especially Dry Kibble — The U.S. Food and Drug Administration is warning dog owners of a possible link between certain dog food brands and a serious form of canine heart disease. (Anna Hoychuk/Shutterstock)

Many pet owners assume the food they scoop into their dog’s bowl is as safe as what they put on their own plates. But an analysis of 79 top-selling dog food products suggests that trust may be misplaced, with “dangerous” levels of heavy metals and other industrial contaminants showing up most prominently in dry kibble, according to Clean Label Project’s Dog Food Category Report.

The nonprofit says it set out to look beyond marketing claims and traditional nutrition labels, focusing instead on real-world contamination in everyday pet diets. Its stated mission is to rely on data and scientific testing rather than “take safety claims at face value” and to “champion and safeguard transparency.”

Dry Food Flagged as Highest Risk

Clean Label Project purchased and tested dry, air-dried, freeze-dried, and fresh or frozen dog foods and ran them through six contaminant panels, covering heavy metals, bisphenols, phthalates, pesticides, glyphosate, and acrylamide. Products were evaluated both per serving and per kilocalorie to mirror typical feeding practices, since most owners measure food by the cup and follow package guidelines.

Across those measures, dry dog food consistently showed the highest levels of arsenic, cadmium, mercury, lead, acrylamide, and the plasticizer DEHP. On average, dry food contained 5.7 times more arsenic, 3.2 times more cadmium, 2.7 times more mercury, and 12.7 times more lead than the group’s benchmark for human consumables. Acrylamide in dry food averaged 24.1 times higher than fresh or frozen dog food, and DEHP averaged 10.8 times higher than fresh or frozen.

Air-dried and freeze-dried products came in second, with heavy metal levels several times higher than the human-consumables benchmark and acrylamide and DEHP significantly elevated compared with fresh or frozen food.

Fresh and frozen dog foods told a different story. They had the lowest levels of contaminants of any format tested and, on average, came in lower than the group’s human-consumables benchmark—which draws data from 3,280 food, beverage, and supplement samples—across all six contaminant panels. Even when the results were recalculated based on recommended serving sizes, dry food remained “exponentially higher” in heavy metals than fresh or frozen diets.

“The love and joy a dog brings to a family are immeasurable,” said Molly Hamilton, executive director of Clean Label Project. “Every dog owner should feel confident that the food they give their pup is nutritious and free from harmful substances.”

How Heavy Metals Get Into the Bowl

According to the report, three common ingredients appear to be key drivers of elevated heavy metals in dry, air-dried, and freeze-dried dog food: meat by-products, added vitamins and mineral premixes, and seafood and plant-based carbohydrates such as grains and root vegetables.

Meat by-products—including livers, lungs, kidneys, spleens, bones, and other tissues left after cuts meant for human consumption are removed—are often processed into meal and used heavily in dry formulas. Heavy metals tend to concentrate in organs and bones, leading to higher levels in finished products that rely on these by-products.

Vitamin and mineral premixes, while necessary to meet dogs’ nutritional needs, can also naturally contain trace metals. Seafood ingredients often carry higher mercury levels, while some grains and root vegetables can accumulate arsenic and other metals from soil. Individually, each source may contribute only modest contamination, but together they can substantially increase heavy metal levels in a single dry dog food formula.

Tools and ‘Clean Sixteen’ List for Worried Owners

To make its findings more practical, Clean Label Project has launched a free Dog Food Contaminant Predictor, which it describes as the largest known dog food ingredient and contaminant database in the world. The tool uses machine learning to estimate likely contamination levels in a product based on its ingredient list.

The group also released its “Clean Sixteen,” a roster of 2026’s highest-rated dog foods for purity drawn from the 79 products analyzed. The list includes fresh and frozen brands such as The Farmer’s Dog, FreshPet, JustFoodForDogs, Jinx, Maev, Nulo, Ollie, Pet Plate, Raised Right, We Feed Raw, and CARU, along with dry options like Hill’s Science Diet Small & Mini and Solid Gold Nutrient Boost.

According to Clean Label Project, these products stood out for having the lowest levels of heavy metals, phthalates, and acrylamide; strong performance across all six contaminant panels; a commitment to fresh, whole, and often human-grade ingredients; transparent sourcing; and use of fresh, frozen, or low-temperature cooking methods that limit processing-related contaminants.