Individual and combined contamination of the toxic metals in commercial cat and dog food | Scientific Reports
How to Assess Toxic Metal Contamination in Pet Foods: A Step-by-Step Guide
Learn how to evaluate levels of lead, cadmium, chromium, mercury and arsenic in commercial dog and cat foods using standardized sampling, digestion and detection methods. Follow these steps to identify contamination hotspots, compare results against regulatory limits, and assess acute dietary risks to pets.
Step-by-Step Guide for Evaluating Toxic Metals in Pet Food
- Collect Representative Samples: Gather a diverse set of dry and canned foods from multiple brands, production years and origins to capture variation in ingredient sources.
- Prepare Samples Safely: Grind dry foods to a uniform particle size; homogenize canned foods. Store under controlled temperature and humidity to prevent contamination.
- Digest and Extract Metals: Use dry ashing for Pb, Cd, Cr and As; microwave digestion for Hg. Follow national standard protocols for acid types, temperatures and durations.
- Measure Metal Concentrations: Apply flame atomic absorption spectrometry for Pb, Cd and Cr; atomic fluorescence spectrometry for Hg and As. Establish calibration curves with certified standards.
- Compare with Regulatory Limits: Determine contamination and exceedance rates against limits set by China’s Hygienical Standard for Pet Feed or relevant local standards for each metal.
- Analyze Combined Contamination: Identify co-occurrence patterns (e.g., Cr + Hg + As in most samples) and quantify how many metals exceed detection or safety thresholds together.
- Assess Dietary Risk: Calculate the acute hazard index (aHI) for different pet weights using worst‐case concentrations and reference doses to estimate potential health risks.
Key Takeaways & Call to Action
Consistent monitoring of toxic metals in pet foods—especially chromium, mercury and arsenic—is essential to safeguard pet health. Adopt these methods in routine quality control and advocate for stricter standards and comprehensive toxicity research on combined metal exposures.