An outbreak of severe iodine-deficiency goitre in a sheep flock in north-east Victoria

Abstract

BACKGROUND: Several outbreaks of goitre, considered to be related to iodine deficiency, occurred in sheep flocks throughout Victoria in 2010. OBJECTIVE: We describe one outbreak in Merino-Border Leicester-cross ewes and their lambs in north-east Victoria that appeared to be associated with increased rainfall and pasture growth, particularly during the preceding summer and autumn. RESULTS: The outbreak was characterised by a four-fold increase in neonatal lamb deaths and goitre, alopecia and poor skeletal development in the lambs. Most cases occurred in lambs born to 2-year-old crossbred ewes that had grazed long, lush perennial pastures throughout their entire pregnancy, whereas few cases oc..