As a last resort, when all other control measures have been appropriately implemented and documented to be ineffective, the most appropriate antimicrobials for preventing diarrhoea in calves are orally administered chlortetracycline (7 mg/kg, every 12 h) and oxytetracycline; chlortetracycline decreases the mortality rate, and oxytetracycline and chlortetracycline
decrease the duration of diarrhoea