Sub-optimum husbandry conditions help the spread of the disease in a lambing flock. Dirty lambing and individual pens, as well as ewes with faecal contamination on their wool, are a hotbed for disease caused by E coli bacteria. If a lamb’s mouth gets contaminated with dung or dirty bedding material before they take in colostrum, bacteria will build up in their intestine, causing illness and, in the majority of cases, death.