Outbreaks of diarrhoea (‘winter scours’) in weaned Merino sheep in south‐eastern Australia

Abstract

A bacterial enteritis caused by pathogenic Yersinia was the cause of the winter scours syndrome in the 24 flocks investigated. The use of molecular testing increased the sensitivity of detection and identification of Yersinia spp. No clear association between weather, WEC and disease was established, suggesting complex interactions between risk factors are more important than any single factor. Sulfonamides should not be routinely used to treat this syndrome. Rather, during an outbreak the targeted use of an effective antimicrobial, such as oxytetracycline, should be integrated with grazing management strategies, including moving affected mobs onto lower risk pastures and decreasing the stocking rate.