Study finds heavy metals in most cat foods, with big gaps by protein source

Clean Label Project tested 100 top-selling cat foods from 62 brands and found heavy metals in nearly every product, with contamination varying sharply by protein source and format. The nonprofit says dry food carried about 3 times more lead than wet or air-dried products, and fish-based foods had much higher mercury levels.

Why it matters: - Cat food contamination is not fully visible on the label. - Heavy metals were widespread across the category, which raises long-term exposure concerns for pets that eat the same food every day. - The study suggests ingredient sourcing, product format and packaging can materially change contaminant levels.

What happened: - Clean Label Project released a new study on 100 top-selling cat food products from 62 brands. - The testing covered dry, wet, air-dried and freeze-dried products. - An independent analytical chemistry laboratory tested the foods using accredited analytical methods. - Results were standardized per 1,000 kilocalories to compare products on equivalent caloric intake.

The details: - Lead was detected in 99% of products, cadmium in 96% and arsenic in 94%. - Nearly 85% of poultry-based foods met Clean Label Project’s purity standard. - Only 25.7% of fish and seafood products met that standard. - Fish and seafood products contained about 18 times more mercury overall. - Fish-based wet foods contained about 28 times more mercury than other wet foods. - Dry cat food contained roughly 3 times more lead than wet or air-dried products. - Each additional plant ingredient among the first 10 ingredients was associated with about 40% higher glyphosate levels. - Canned and pouched foods carried about 5 times more DEHP than bagged products where DEHP was detected. - Fish and seafood products contained about 2.5 times more cadmium than other products. - Nearly half of fish and seafood products ranked among those with the highest mercury levels. - No poultry-based products ranked among those with the highest mercury levels.

Between the lines: - The results do not indicate contaminants were intentionally added to cat food. - Heavy metals can enter products through soil, water, marine environments and raw ingredients. - Other contaminants may come from processing or packaging. - The study suggests lower contaminant levels are achievable with ingredient sourcing, supplier testing and stronger quality controls. - More than one-third of products had a first-listed ingredient that was outnumbered by another ingredient category within the first 10 ingredients. - Products with more plant ingredients near the top of the label tended to have higher glyphosate levels. - Products where plant ingredients outnumbered the named meat or fish also carried more lead. - The label may not fully reflect the broader ingredient mix consumers are feeding their cats.

What's next: - Clean Label Project plans to continue independent testing across the pet food category. - The organization says the cat food report is part of a broader effort following its dog food study earlier this year. - The full Cat Food Category Report and the Clean Sixteen lists for wet and dry cat foods are available online.

The bottom line: - Clean Label Project’s testing points to a simple takeaway: protein source and product format matter, and cat food labels alone do not reveal the full contamination picture.