NAVLE Gastrointestinal and Digestive

Bovine Hemorrhagic Bowel Syndrome Study Guide

Hemorrhagic Bowel Syndrome (HBS), also known as Jejunal Hemorrhage Syndrome (JHS), is a sporadic, acute, and often fatal intestinal disease primarily affecting adult dairy cattle.

Overview and Clinical Importance

Hemorrhagic Bowel Syndrome (HBS), also known as Jejunal Hemorrhage Syndrome (JHS), is a sporadic, acute, and often fatal intestinal disease primarily affecting adult dairy cattle. First described in 1991, HBS is characterized by segmental necrohemorrhagic enteritis of the small intestine, predominantly the jejunum, leading to intramural hematoma formation and luminal obstruction.

The syndrome has emerged as an economically significant disease in North American and European dairy herds, with case fatality rates reported between 85-100%. Affected animals typically die within 12 to 48 hours after onset of clinical signs. While the exact etiology remains unclear, Clostridium perfringens type A and Aspergillus fumigatus have been implicated as potential causative agents.

High-YieldHBS is a high-priority differential for any adult dairy cow presenting with acute colic, decreased milk production, and dark tarry feces (melena). The combination of peracute onset, high mortality, and characteristic "blackberry jelly" blood clots in feces is pathognomonic.
Parameter Description
Species Affected Primarily dairy cattle; occasionally beef cattle
Breed Predisposition Brown Swiss overrepresented in multiple studies; Holstein Friesian commonly affected
Age Adult cattle (typically mature, multiparous cows)
Stage of Lactation First 3 months of lactation (highest risk period); peak at 60-140 days postpartum
Seasonality Higher incidence during cold months (winter)
Incidence Rate Animal-level: 1-2%; Herd outbreaks can exceed 10% morbidity

Etiology and Pathophysiology

Proposed Etiologic Agents

The exact cause of HBS remains uncertain and is believed to be multifactorial. Two primary organisms have been implicated:

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