Hair mercury concentrations in cats and dogs in central Japan

Hair mercury concentrations were measured in 41 cats and 34 dogs living in Kanagawa, Saitama and Tokyo Prefectures. Total mercury concentrations measured by atomic absorption spectrometry were significantly higher (P < 0.01) in cats [7.40 parts per million (ppm) in males and 7.45 ppm in females] than in dogs (0.99 ppm in males and 0.66 ppm in females). Mercury in cat hair was correlated with age (P < 0.01) and higher in cats fed with foods prepared by the owners than in those fed with commercial pet foods. Mercury concentrations in the animals' foods were markedly higher in fresh tuna (0.153 ppm) than in commercial pet foods (0.008-0.014 ppm).