This report describes the clinical and pathological findings in a case of acute zinc poisoning in a young dog. The puppy suffered four days of progressively more severe vomiting and diarrhoea. Jaundice and pale mucous membranes, severe haematemesis and haemoglobinuria were other findings. Despite intensive therapy, the dog died a few hours after hospitalisation. Postmortem examination revealed a metallic foreign body in the stomach, catarrhal gastritis, hepatomegaly and enlarged, dark kidneys. Histology showed hepatic centrilobular vacuolar degeneration, haemoglobinuric nephrosis with early tubular necrosis, haemosiderosis and extramedullary haematopoiesis, as well as neuronal damage. The foreign body was mainly composed of zinc. Plasma zinc values were markedly raised (34.5 microg/ml; normal range 0.8 to 1.0 microg/ml). Pathophysiological mechanisms of zinc poisoning are discussed.