Hemorrhagic bowel syndrome (HBS) is a highly fatal, sporadic acute digestive tract disease of adult dairy cattle. Cows with HBS develop large blood clots in the intestine, resulting in obstruction and severe bowel size increase. Clinical signs associated with HBS include acute enteritis, dehydration, shock and sometimes abdominal pain. Cows often die within 12 to 36 hours following onset of clinical signs.

Although the exact cause of HBS is unknown, it is thought to be associated with Clostridium perfringens or Aspergillus fumigatus.