Exposure profile of four classes of emerging pesticides in pet dog and cat serum from Wuhan, China.

Emerging pesticides exposure in companion animals remains understudied despite growing concern over environmental contamination and pet health. We quantified 24 emerging pesticides and their metabolites in serum samples from 60 pet dogs and cats in Wuhan, China, using a salting-out assisted acetonitrile extraction method coupled with HPLC-MS/MS. A total of 19 compounds were detected in cats and 16 in dogs, with cats exhibiting significantly higher total pesticide concentrations (median: 4.90 ng/mL) than dogs (3.02 ng/mL). Organophosphates (OPs), particularly chlorpyrifos as indicated by its metabolite 3,5,6-trichloro-2-pyridinol (TCPY), were the predominant pesticide class in dogs, whereas pyrethroids (PYRs) and the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) were more abundant in cats. TCPY, 2,4-D and N-desmethyl acetamiprid (a neonicotinoid metabolite) were the most frequently detected pesticides across both species. Estimated daily intakes (EDIs) of these three dominant pesticides (0.0002-0.0649 μg/kg bw/day) were well below established chronic reference doses (cRfDs; 0.3-71 μg/kg bw/day), suggesting limited individual pesticide risk. However, over 95 % of serum samples contained multiple pesticide residues, raising concerns about potential cumulative and synergistic effect. These findings underscore the need for expanded biomonitoring efforts to better understand emerging pesticide exposure in pets and their role as sentinels for household and environmental chemical risks.