Characterization of the Fecal Bacterial Microbiota of Healthy and Diarrheic Dairy Calves

Gomez, D.E.; Arroyo, L.G.; Costa, M.C.; Viel, L.; Weese, J.S.

N eonatal calf diarrhea accounts for most of the morbidity and mortality in calves, accounting for >50% of total deaths, and has a large impact on the economy of dairy farms. 1 Although pathogenic bacteria (Escherichia coli, Salmonella spp), viruses (rotavirus, coronavirus), and protozoa (Cryptosporidium spp) can be found in a large percentage of cases, the etiology of disease may be hard to discern because of the common presence of coinfections (>1 pathogen identified in the same patient) 2 and the fact that most organism also can be found in healthy individuals. These observations suggest that the cause of diarrhea is complex rather than associated with a single pathogen. Diagnosis of enteric disease also is likely affected by the complexity of the microbiota (ie, the rich and diverse polymicrobial community present in the gut).