New Cat Food Study Finds Heavy Metals Widespread and Major Differences by Protein Source

Testing of 100 top-selling cat foods found dry products carried roughly 3x more lead than wet or air-dried foods

DENVER, CO, UNITED STATES, October 2, 2026 /EINPresswire.com/ — Clean Label Project^®, a national nonprofit focused on truth and transparency in consumer product labeling, today released a new study examining contaminants in 100 of the nation’s top-selling cat food products across 62 brands.

The study tested products for more than 122 industrial and environmental contaminants and toxins, including heavy metals, phthalates, pesticides, herbicide residues and processing by-products. The findings show that while heavy metals are widespread across the cat food category, contaminant levels can vary significantly depending on protein source, food format and ingredient composition.

The new research expands Clean Label Project’s ongoing examination of the pet food category following its dog food study released earlier this year, giving cat owners a similar look at contaminants that are not disclosed on traditional product labels.

“Cat owners trust that the food they put in their pet’s bowl every day is safe, but there is an enormous amount of information they simply cannot get from the label,” said Molly Hamilton, Executive Director of Clean Label Project. “Finding heavy metals in nearly every product we tested is concerning, but what is especially striking is how dramatically contaminant levels can vary depending on the protein source and type of food.”

Key findings from the study include:
– Heavy metals were widespread. Lead was detected in 99% of products, cadmium in 96% and arsenic in 94%.
– Protein source mattered. Nearly 85% of poultry-based foods met Clean Label Project’s purity standard, compared with 25.7% of fish and seafood products.
– Fish-based foods had far more mercury. Fish and seafood products contained about 18x more mercury overall, and fish-based wet foods about 28x more than other wet foods.
– Dry food carried more lead. Dry cat food contained roughly 3x more lead than wet or air-dried products.
– More plant ingredients meant more herbicide residue. Each additional plant ingredient among the first 10 was associated with about 40% higher glyphosate levels.
– Packaging mattered too. Canned and pouched foods carried about 5x more DEHP than bagged products where it was detected.

Seafood stood out as one of the clearest patterns in the study. Nearly half of fish and seafood products ranked among those with the highest mercury levels, while no poultry-based products did. Fish-based products also contained approximately 2.5 times more cadmium than other products.

The findings do not mean these contaminants are intentionally added to cat food. Heavy metals can occur naturally in soil, water and marine environments and enter products through both animal and plant ingredients. Other contaminants may be introduced through processing or packaging. Clean Label Project’s analysis found that lower contaminant levels are achievable through ingredient sourcing, supplier testing and stronger quality controls.

What the Label Doesn’t Tell You

The study also examined whether the first ingredient listed on a cat food package provides consumers with a complete picture of what is in the product.

In more than one-third of products tested, the first-listed ingredient was outnumbered by ingredients from another category within the first 10 ingredients. In many cases, a meat or fish ingredient appeared first, but the broader ingredient list contained multiple plant-based ingredients.

Products with more plant ingredients near the top of the ingredient list tended to contain higher levels of glyphosate, while products where plant ingredients outnumbered the named meat or fish also carried more lead.

“Cats may eat the same food every day for years, so even small differences in what is in that food can matter over time,” Hamilton said. “The good news is that our testing shows lower contaminant levels are achievable. Cat owners deserve greater transparency, and brands have an opportunity to look more closely at their ingredients, sourcing and finished products to reduce unnecessary exposure.”

Expanding the Look at Pet Food

The cat food study follows Clean Label Project’s dog food research released earlier this year and represents the organization’s continued expansion of independent testing across the pet food category.

Together, the studies are intended to give pet owners greater visibility into how ingredients, sourcing, processing and product format may influence contaminants in foods their pets often consume day after day.

Clean Label Project purchased 100 cat food products from 62 brands across three product formats: dry, wet, and air-dried or freeze-dried. Testing was performed by an independent analytical chemistry laboratory using accredited analytical methods.

Because wet and dry foods differ significantly in water content and calorie density, results were standardized on a per-1,000-kilocalorie basis, allowing products to be compared based on equivalent caloric intake rather than simply by food weight.

The full Clean Label Project Cat Food Category Report, along with the organization’s Clean Sixteen lists recognizing the highest-rated wet and dry cat foods for purity, is available at cleanlabelproject.org.

About Clean Label Project
Clean Label Project is a nonprofit dedicated to promoting transparency in consumer product labeling and holding manufacturers accountable through independent testing for environmental and industrial contaminants. The organization’s mission is to uncover hidden risks associated with environmental contaminants and toxins found in everyday products, with the guiding principle that reducing contaminants is critical to safeguarding long-term health.

To learn more, visit cleanlabelproject.org.

Kate Stuard
Clean Label Project
kate@dsjstrat.com

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