Chronic copper poisoning in dairy cows.

Chronic copper poisoning in a dairy herd fed supplementary copper is recorded. Most cows received 11 g of copper sulphate per day but high milk producers received 22.0 g and within 6 months, 3 of them became ill and died. The signs shown by the 3 cows were anorexia, decreased milk production, frequent recumbency and jaundice. Within 4 days of showing signs, the cows died. The autopsy findings were dehydration, anaemia, jaundice, liver damage and intestinal haemorrhage. Liver copper values varied from 1,250 to 2,410 ppm DM.