Mycotoxins and Beyond: Unveiling Multiple Organic Contaminants in Pet Feeds Through HRMS Suspect Screening

This study evaluated 65 commercially available pet feed samples, including 33 cat feeds and 32 dog feeds (dry and wet formulations), for the presence of organic contaminants. These included mycotoxins, pesticides, pharmaceutical residues/veterinary drugs, and plant-based bioactive compounds. A suspect screening strategy was employed using QuEChERS extraction followed by LC-LTQ/Orbitrap HRMS analysis. A total of 29 compounds were tentatively identified within 186 detections. In total, 76.9% of the samples were contaminated with mycotoxins. Aflatoxins (B1, B2, G1, and G2), T2 toxins, and HT2 toxins were dominant, with Aflatoxin B1 occurring in 33.8% of the samples and exhibiting a higher prevalence in dry feeds than in wet feeds. Pesticides were present in 72.0% of the dry formulations, including aclonifen and pirimiphos-methyl, but were present in only 11% of the wet formulations. Plant-based bioactive compounds, including phytoestrogens, were identified in 51% of the samples, highlighting toxicologically relevant candidates that merit prioritization for targeted confirmation, particularly in cat feeds. Pharmaceuticals were found in 23.8% of dry feeds (sparfloxacin and fumagillin). Overall, the HRMS-based, standard-free suspect screening workflow provides an early-warning overview of multi-class co-occurrence patterns in complex pet feed matrices and supports the prioritization of candidates for subsequent confirmatory analysis.