Chronic copper poisoning of sheep in Nigeria

An outbreak of chronic copper poisoning in sheep is described. At least 145 out of 687 sheep (21.1%) on a government farm died during a period of 2 months. The clinical and post-mortem picture was one of sudden, profound intravascular haemolysis and subsequent jaundice. Mortality approached 100%. Plasma copper levels ranged from 22 to 76 mumol/litre. There was no obvious source of exogenous copper. Possible causes of the elevated copper levels are discussed.