Neonatal Calf Diarrhea: Purification and Electron Microscopy of a Coronavirus-like Agent

SUMMARY A previously unreported coronavirus-like agent was detected in diarrheal fecal material obtained from neonatal calves in 19 herds from western Nebraska. Techniques for purification and the electron microscopic morphologic features of the coronavirus-like agent are described. Gnotobiotic, colostrum-deprived, and colostrum-fed neonatal calves were experimentally inoculated with coronavirus-like agent, and diarrhea was produced in all calves. Coronavirus-like agent was seen in the feces of each of the experimentally inoculated calves when diarrheal fecal samples were fractionated, and the fractions were examined by electron microscopy.