In April 2025, researchers from Huazhong Agricultural University, in collaboration with two veterinary institutes in China, conducted an analysis of toxic metal content in pet food products imported into the Chinese market from the United States, Spain, Thailand, Germany and New Zealand. The study examined 45 cat food and 48 dog food samples produced between 2021 and 2022, using nationally standardized methods to detect levels of heavy metals.
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These metals— chromium (Cr), cadmium (Cd), lead (Pb), arsenic (As) and mercury (Hg)—can enter the food supply through environmental pathways such as contaminated soil, mining activities, the use of livestock manure and chemical fertilizers. The primary objective of the study was to assess contamination levels and evaluate the potential health risks to pets from exposure to these substances.
The study found that more than 25% of all samples contained all five heavy metals. In addition, the majority of food samples were found to contain at least three heavy metals (Cr, Hg, As). By comparison, only around 2% of the samples contained two heavy metals, while none contained fewer than two.
Potential health risks were assessed based on the ratio between exposure levels and the acute reference dose for toxicity. In the absence of pet-specific values, the researchers used reference doses for mammals. Results indicated that both cats and dogs are at risk of dietary exposure, with chromium presenting the highest risk, followed by lead and arsenic. Risks were especially pronounced in animals with lower body weight.
The analysis found that levels of contamination varied by food type. Dry pet food had the highest concentrations of toxic metals, with several samples exceeding legal limits for lead and chromium. By contrast, canned food samples—while still posing potential dietary risks—remained within legal limits. The study also emphasized that pets generally live longer than farm or lab animals, increasing the risk of toxic metal accumulation over time, even at low exposure levels.
These findings highlight the presence of heavy metals in a significant portion of pet food products tested. The authors recommend better formulation practices, tighter manufacturing controls, and greater transparency around ingredients to support safer choices for pet owners.
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To read the study, follow this link.