The present study examined the effects of catechin administration on performance, faecal quality, mineral, and malondialdehyde (MDA) levels in 12 Belgian Malinois puppies at 6 months of age. Dietary supplementation of catechin was not observed to have a significant (P> 0.05) effect on live weight, faecal pH, DM, ether extract, crude fiber, ash, and faeces score. The catechin significantly (P< 0.05) decreased plasma MDA concentration. Serum Ca, K, Mg, Fe, Zn, Cu, Cr, Mn, and Co levels were not affected (P> 0.05) by the catechins; however serum Se levels were determined at a high level (P< 0.05) compared to the control group. The levels of Zn (P< 0.05), Mg (P< 0.01), and Cu (P< 0.05) in the faeces increased significantly but there were no differences (P> 0.05) in the levels of other minerals. It may be concluded that administration of catechins together the diet of Belgian Malinois puppies showed antioxidant effects without imparting any negative effects on live weight, feed intake, faecal quality, and serum trace and macro mineral levels, however elimination via faeces of Zn, Mn, and Cu increased with catechin addition.