In 23 cows suffering from a secondary indigestion, in most cases with septicaemia, the syndrome of functional pyloric stenosis or vagal indigestion developed. The signs were anorexia, ruminal distension with fluid material, abomasal reflux into the ruminoreticulum, dehydration, hypochloraemic, hypokalaemic metabolic alkalosis and uraemia. These signs often disappeared after treatment of both the primary causative disease and the secondary indigestion. The importance of recognising this condition is emphasised, because the serious signs of the secondary indigestion may dominate the causative disease. The prognosis depends upon the causative disease and is not necessarily bad.