Multiple contaminant detection in commercially available chicken-based cat kibbles in Italy

The increasing consumption of commercially available pet food raises growing concerns regarding the possible presence of contaminants and their potential impact on companion animal health. In this sense, pet food, particularly chicken-based, may become the main vehicle for environmental and anthropogenic pollutants and the underlying cause of most inflammatory pathologies. This research aimed to investigate the possible presence of contaminants or their residues in 29 commercially available chicken-based cat kibbles using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) for antibiotics, per-and polyfluoroalkyl substances (PFAS), Inductively Coupled-Plasma Mass Spectrometry (ICP-MS) for toxic metals, and Enzyme-Linked Immunosorbent Assay (ELISA) for bisphenol A (BPA). Microplastics (MPs) were determined using sodium chloride (NaCl) density separation extraction, followed by repeated recovery steps, on-filter oxidative digestion, and microscopic inspection. Chlortetracycline residues were present only in 1 out 29 samples (79 ± 35 μg/kg), doxycycline residues were detected in 4 out of 29 samples (mean concentration 80.25 ± 35.5 μg/kg), polyfluoroalkyl substances in 7 out of 29 samples (mean 5-carbon perfluoropentanoic acid (PFPeA), 6-carbon compound perfluorohexanoaic acid (PFHxA), and 9-carbon perfluorononanoic acid (PFNA) concentration 0.167, 0.261, and 0.100 μg/kg, respectively), toxic metals in 28 out of 29 samples (mean Pb, Cd, As concentration 140.42 ± 23.79, 27.06 ± 4.73, and 69 ± 11.85 μg/kg, respectively), while BPA (mean concentration 1.29 ± 0.19 μg/kg) and MPs [fibers (65%) and fragments (35%)] were detected in all samples. The lack of maximum residual limits and the chronic dietary exposure to complex contaminant mixtures may pose health risks to cats due to cumulative and synergistic effects. These findings underscore the need for continuous, stricter monitoring of contaminants and their residues in raw materials, as well as for a comprehensive risk assessment to ensure pet food safety.