Infectious agents associated with neonatal calf disease in southwestern Idaho and eastern Oregon.

Over a 2-year period, 296 episodes of disease involving 226 1-to-60-day-old calves were referred to the Caldwell Veterinary Teaching Center. Infectious disease agents were found in 96% of the cases. Salmonella spp were the most frequently isolated agents from dairy calves, whereas coronavirus was the agent most commonly associated with diarrhea in beef calves. Multiple agents were found in 20% of the dairy calves and in 12% of the beef calves. Salmonella dublin, which is associated with severe disease in man, made up a large percentage of the Salmonella spp isolated (40%). In vitro drug sensitivities indicated that a high percentage of Salmonella and Escherichia coli were resistant to drugs, especially to the drugs commonly used to treat calf diarrhea.