Diagnosis and treatment of copper poisoning caused by accidental feeding on poultry litter in a sheep flock

We report a case of chronic copper poisoning in a flock of 182 grazing dairy sheep in Thessaly, Central Greece. Five ewes were found dead during the course of a week. The diagnosis of copper poisoning was confirmed by necropsy examination, blood test results, and abnormally high copper levels in liver and kidney samples. A field investigation revealed the source of copper as a litter heap from a broiler farm to which the sheep had accidental access during their movement between the milking parlour and the grazing area. Access to the litter was subsequently blocked and all sheep were provided with 50 g of a salt/gypsum/sodium molybdate mixture (90.0: 9.8: 0.2, w/w) mixed in 500 g of concentrate feed daily, for a period of 5 weeks. Follow-up blood samples were taken 3 and 8 wk after the initial diagnosis. A reduction in aspartate aminotransferase activity indicated the source of copper had been eliminated and the subsequent treatment was successful