Determination of Heavy Metal Contamination in Premium and Supermarket Brands of Extruded Feline and Canine Food in the South African Market

The recent increase in pet food recalls due to contamination and the increased risk of disease has highlighted the need for the screening of canine and feline pelleted food. Heavy metals, an often-overlooked contaminant, has been highlighted for its role in the development of companion animal disease. Therefore, it is imperative that heavy metal content in these commercially available pet foods is investigated. In this study, premium (n = 14) and supermarket brands (n = 17) of extruded cat and dog food were analyzed for the presence of As, Cd, Co, Cu, Fe, Pb, Hg, Ni and Zn using ICP-OES and Hg by HGAAS. Collectively, extruded dog food brands produced mean concentrations of 7.47 (As), 6.23 (Cd), 4.01 (Co), 16.72 (Ni), 3.99 (Pb), 0.47 (Hg), 35.59 (Cu), 529.53 (Fe) and 25.25 (Zn) mg/kg, whilst cat food brands contained 2.92 (As), 3.15 (Cd), 2.44 (Co), 4.26 (Ni), 7.24 (Pb), 0.16 (Hg), 38.08 (Cu), 389.14 (Fe) and 195.12 (Zn) mg/kg. Canine brands exceeded maximum tolerable limits (MTLs) more than feline with red meat proteins containing higher total heavy metal levels followed by poultry, fish and meat medley formulations. Furthermore, premium brands displayed higher levels of heavy metals exceeding MTLs than supermarket brands which were lower priced.