Congenital biliary atresia and jaundice in lambs and calves

SUMMARY An outbreak of congenital biliary atresia and jaundice is described, in which ap proximately 300 crossbred lambs and 9 crossbred calves died. The affected animals failed to thrive, developed jaundice and white scours and died within 4 weeks of birth. A common feature of this outbreak and a similar occurrence 24 years previously was the grazing of plants growing on the exposed silt foreshores of Burrinjuck Dam by ewes and cows in the early stages of pregnancy. Epidemiological and pathological findings suggested that a toxic insult to the foetus in early gestation caued choledysgenesis and biliary atresia, leading to diffuse, subacute to chronic cholangiohepatopathy and cirrhosis.