Study Finds Heavy Metals Including Lead in Nearly All Tested Cat Foods

Clean Label Project, a U.S. consumer-health nonprofit that also runs its own pet-food certification program, published a study on October 2, 2026 reporting that heavy metals and other industrial contaminants were detected in almost every commercial cat food it tested.

What the study tested and found

According to Clean Label Project, an ISO 17025-accredited laboratory analyzed 100 cat food products from 62 brands, split between dry kibble (31 products), wet, canned or pouch foods (40) and air-dried or freeze-dried foods (29). The lab screened for more than 122 contaminants — including heavy metals, the plastic chemical DEHP, bisphenols, pesticide residues and the herbicide glyphosate — using mass-spectrometry methods (ICP-MS for metals, LC-MS/MS for organic compounds). Results were standardized per 1,000 kilocalories so formats with different calorie density could be compared.

Why fish-based formulas stood out

The study found a sharp split by protein source: 84.8% of poultry-based products met Clean Label Project's own quality threshold, compared with 25.7% of fish and seafood products. Clean Label Project attributes the gap mainly to mercury and cadmium, saying both accumulate in marine animals through the food chain. The organization's own data did not link lead or glyphosate levels to a specific protein source; lead levels were linked instead to product format (dry versus wet or air-dried), and glyphosate detection was linked to the amount of plant ingredients in a formula.

Industry and regulatory context

The Pet Food Institute, a trade group representing manufacturers, said companies maintain food safety and quality assurance programs that include ingredient specifications, supplier verification, testing protocols, traceability systems and preventive controls intended to keep products safe and consistent, according to comments reported by WISH-TV. Its chief executive, Elise Fennig, said cat owners should feel confident that pet food is produced according to rigorous regulatory and quality standards, the outlet reported.

Clean Label Project executive director Molly Hamilton said the absence of safety standards does not mean a contaminant is safe. 'Most guidelines are designed for farm animals, not kittens or 15-year-old housecats,' she said, according to WISH-TV. Clean Label Project did not report any cat illnesses or deaths linked to the tested products; its findings describe contaminant presence and levels, not confirmed harm to specific animals.

What pet owners can do, according to the study

• Rotate protein sources rather than feeding only fish-based formulas, since seafood showed the highest mercury and cadmium levels.
• Consider wet or air-dried formats over dry kibble, which showed roughly three times more lead on average.
• Check full ingredient lists rather than relying on the first listed ingredient alone; Clean Label Project found that in 35 of the 100 products, the first-listed ingredient was outnumbered within the first ten ingredients by items from a different category, which it described as a form of ingredient splitting.
• Be cautious with foods listing plant ingredients high on the label, since glyphosate detection correlated with higher plant content.
• Ask manufacturers whether they conduct and share regular finished-product contaminant testing.

These points reflect recommendations attributed to Clean Label Project in its report and in media coverage of the study; they are not independent medical or veterinary advice, and the organization's business model includes paid certification for brands such as Bixbi, Freshpet and Smalls, which it lists as meeting its standards.