Widespread PFAS contamination in pet food: Dietary sources and health risks to companion animals

Despite the growing concern over per- and polyfluoroalkyl substances (PFAS) exposure in companion animals, dietary intake through commercial pet food remains poorly characterized. In this study, we conducted a comprehensive analysis of 100 commercially available pet food products for dogs and cats in Japan, encompassing both dry and wet types, to quantify 34 target PFAS compounds. PFAS were frequently detected, with concentrations varying by food type, ingredients, and country of origin. Fish-based products contained elevated levels of perfluorooctanesulfonic acid (PFOS), perfluoroundecanoic acid (PFUnDA), and perfluorotridecanoic acid (PFTrDA), and regional patterns suggested the influence of Asian-specific PFAS sources such as F-53B. Hazard quotient (HQ) assessments based on EFSA tolerable weekly intakes indicated that average HQs exceeded 1 for both dogs and cats in several products, signaling potential health risks. However, due to the lack of species-specific toxicokinetic information for dogs and cats, the EFSA-based risk characterization presented here should be interpreted as a preliminary assessment. Although dry food had higher PFAS concentrations when converted to feeding amounts, estimated exposure was higher for wet food due to higher consumption. These findings provide the first evidence of ingredient-driven and country-of-origin-dependent PFAS contamination in pet food. Fish used as ingredients are a significant source of exposure to PFAS. They also highlight the urgent need for regulatory oversight and toxicological evaluations specific to companion animals. These animals serve as vulnerable populations and as sentinels of human co-exposure in domestic environments.