Fish-based pet food may expose cats and dogs to forever chemicals
New Scientist
February 20, 2026
AI-Generated Deep Dive Summary
A recent study reveals that fish-based pet foods often contain concerning levels of PFAS (perfluoroalkyl and polyfluoroalkyl substances), commonly known as "forever chemicals." These substances, which can persist in the environment for centuries, were found in numerous commercial dog and cat food brands, with some products exceeding European health agency thresholds for human exposure. While no immediate health emergency is indicated, the findings underscore a critical need for greater monitoring of contaminants in pet products and a deeper understanding of their potential risks to companion animals.
PFAS are artificial chemicals widely used in industrial and consumer products, including non-stick cookware, fire extinguishers, and water-repellent fabrics. They can accumulate in the environment and in living organisms, leading to serious health issues such as liver damage, certain cancers, and endocrine disorders in humans. While research on their effects on pets is limited, studies suggest that PFAS exposure could contribute to liver, thyroid, kidney, and respiratory problems in cats and dogs.
The study, conducted by researchers at Ehime University in Japan, analyzed 48 dog food and 52 cat food products sold in Japan between 2018 and 2020. They measured concentrations of 34 types of PFAS and calculated daily intake levels for pets based on body weight. Several products exhibited moderate to high PFAS levels, with some exceeding EFSA’s (European Food Safety Agency) recommended limits for human exposure. Fish-based cat foods, particularly those from Asia, the U.S., and Europe, showed the highest contamination, while grain-based dog foods often had lower levels.
The researchers hypothesize that PFAS contamination in pet foods may stem from agricultural runoff or fish byproducts used as ingredients. Since PFAS are globally prevalent, especially in water systems, they can accumulate in aquatic food webs and concentrate in seafood. This highlights the need for more standardized monitoring of PFAS in pet products, as pets share our environment and can serve as indicators of chemical exposure.
The study’s lead author, Kei Nomiyama, emphasizes that while current findings do not indicate an immediate health crisis, they
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Originally published on New Scientist on 2/20/2026