Neonatal calf scours have been a costly problem for cattlemen for many years. The disease strikes all types of cattle operations although it is most devastating in the intensified cow-calf herd or dairy herd. For the purposes of this paper neonatal calf scours will be defined as that condition of young calves, usually under ten days of age, which is characterized clinically by severe diarrhea and dehydration. with death occurring within a few days if treatment is not begun at the onset and by the absence of lesions characteristic of other diseases.