POISONING OF DAIRY HEIFERS BY MERCUROUS CHLORIDE

Mercury poisoning was diagnosed in four dairy heifers, three of which died. The clinical signs were variable and included salivation, excess ive thirst, extreme depression and severe diarrhoea. Postmortem examin ations revealed inflammation and ulceration of the alimentary tract, p ulmonary and cardiac haemorrhages, pallor of the kidney cortices and p erirenal oedema. The kidney mercury concentrations were in the range 5 8 to 91 mu g/g wet tissue. It is believed that the animals were poison ed by the ingestion of soil contaminated with mercurous chloride.