The effects of dietary zinc on zinc absorption and excretion were evaluated with six 12-week-old beagles. The dogs were fed a commercial dry food later supplemented with 2 and 4 mg/kg of body weight per day of either zinc sulphate, zinc acetate or zinc oxide. The concentrations of zinc in the urine and faeces of all treatment groups were increased depending on the type of zinc salts and the dosage in the diet (P < 0.05). The apparent absorption of zinc salts ranged from 0.20 to 0.36. The zinc salt supplements at both dosages did not affect the digestibility of crude protein, fat and fibre. The zinc concentration in plasma varied with the type of zinc salt and with the dosage. The mean concentrations ranged from 61 +/- 1.46 mug to 73 +/- 1.57 mug/dl in the unsupplemented groups, whereas it was 115 +/- 2.33 mug/dl in the group supplemented with zinc acetate at the highest dosage.