Chronic copper toxicity of ruminants

Abstract

There has been an active interest in the toxicology of copper since the middle of the 19th century and a review by Davenport (1953) covers the early work on the hazard to man and animals of both the acute and chronic forms. Review material specific to chronic copper poisoning in farm livestock has also been published by Broughton & Hardy (1934), Eden (1940), Todd (1962) and Bull (1964).The first description of true chronic copper poisoning in farm animals would seem to be that of Mallory (1925) who produced the condition experimentally in sheep. Beijers (1932) described similar symptoms in sheep grazing orchards which had been sprayed with a copper fungicide, and 2 years later Broughton & Hardy (1934) published their detailed experimental investigations showing the dangers of excessive copper intakes to sheep. The similarity between the symptoms described in these reports and those of ‘yellows’ or ‘toxaemic jaundice’ in Australia was recognized (Bull, 1964) and the experiments of Albiston, Bull, Dick & Keast (1940) confirmed that this naturally-occurring condition was of similar origin. The importance of chronic copper poisoning as a nutritional hazard was, therefore, fully established.