Overview
Hemorrhagic Bowel Syndrome (HBS), also known as jejunal hemorrhage syndrome, is a sporadic, acute, and often fatal disease primarily affecting high-producing dairy cows. It is characterized by sudden intraluminal hemorrhage and clot formation in the small intestine, leading to obstruction, necrosis, and rapid clinical deterioration. SAGE Journals
Etiology and Pathogenesis
- Causative Agents: The exact cause of HBS remains uncertain. Clostridium perfringens type A and Aspergillus fumigatus have been implicated, but their roles are not definitively established. Ruminants, DVM 360
- Pathogenesis: The disease involves acute, localized, necrotizing, hemorrhagic enteritis of the small intestine, leading to intraluminal blood clot formation. This results in physical obstruction, accumulation of intestinal contents, ischemia, necrosis, and potentially peritonitis. Merck Veterinary Manual
A. Characteristic dark-red bloody lesion in the intestine of HBS, resulting in luminal obstruction. B. Transverse section of the intestinal lesion after formalin fixation. Intramural hematoma (asterisk) is found. The mucosa is detached from the intestinal wall (arrowheads). C. Intramural hematoma and lumen (asterisk). Massive hemorrhage is observed in the submucosa and lamina propria. The mucosal layer is almost intact. These are no hemorrhagic lesions in the lumen. HE stain, Bar=2.0 mm. D. Fibrinoid necrosis of the vascular wall (arrowheads) in the submucosa of the lesion. HE stain, Bar=200 µm. E and F. Gram positive and anti-Clostridium antibody positive short bacilli in surface of necrotic mucosa. Gram stain, Bar=500 µm (E) and Immunohistochemistry, Bar=50 µm (F). Reference.
Epidemiology
- Affected Population: Primarily mature, high-producing dairy cows, especially within the first 100 days of lactation. PAHC+2DAIReXNET+2PAHC+2
- Risk Factors: High-energy, low-fiber diets; feeding total mixed rations (TMR); sudden dietary changes; and environmental stressors. DAIReXNET
- Seasonality: Higher incidence reported during colder months. Merck Veterinary Manual
Clinical Signs
- Sudden anorexia and profound depression.(Ruminants)
- Sharp decline in milk production.PAHC+3APHIS+3Merck Veterinary Manual+3
- Abdominal distension and signs of colic (e.g., kicking at the abdomen).Merck Veterinary Manual
- Dark, tar-like feces containing blood clots.Merck Veterinary Manual+4PAHC+4Labs Home+4
- Dehydration, tachycardia, and pale mucous membranes.Merck Veterinary Manual+1Ruminants+1
- Rapid progression to recumbency and death within 12 to 36 hours if untreated. DAIReXNET
Diagnosis
- Clinical Evaluation: Based on sudden onset of signs and characteristic fecal appearance.
- Rectal Examination: May reveal distended loops of small intestine.Ruminants+1APHIS+1
- Ultrasonography: Can identify dilated intestinal loops and intraluminal clots.
- Laboratory Tests: May show electrolyte imbalances, dehydration, and elevated serum L-lactate levels. Merck Veterinary Manual
- Definitive Diagnosis: Confirmed via exploratory laparotomy or necropsy revealing segmental hemorrhagic enteritis with intraluminal blood clots. (Merck Veterinary Manual)
Treatment
- Surgical Intervention: Early surgery to manually massage and break down clots or perform enterotomy to remove clots. In cases with necrotic intestine, resection and anastomosis may be necessary. Labs Home,PMC
- Medical Management: Supportive care with intravenous fluids, electrolytes, anti-inflammatory drugs, and antibiotics. However, medical treatment alone is often unsuccessful. DVM 360
- Prognosis: Generally poor, with high mortality rates even with aggressive treatment.
Prevention
- Dietary Management: Avoid sudden dietary changes; ensure adequate fiber intake; and monitor TMR quality. DAIReXNET
- Environmental Management: Reduce stressors and maintain consistent feeding schedules.
- Vaccination: Some anecdotal reports suggest a protective effect of Clostridium perfringens type C and D vaccines, but scientific evidence is lacking. DVM 360
NAVLE-Style Multiple-Choice Questions
Question 1:
A 5-year-old high-producing dairy cow presents with sudden anorexia, abdominal distension, and dark, tar-like feces containing blood clots. What is the most likely diagnosis?
A. Left displaced abomasum
B. Hemorrhagic bowel syndrome
C. Cecal dilatation
D. Intussusception
E. Abomasal ulcer
Correct Answer: B. Hemorrhagic bowel syndrome
Explanation: The acute onset of signs, including dark, bloody feces and abdominal distension in a high-producing dairy cow, is characteristic of HBS.PAHC
Question 2:
Which of the following is a known risk factor for the development of hemorrhagic bowel syndrome in dairy cattle?
A. High-fiber diets
B. Low milk production
C. Feeding total mixed rations
D. Grazing on lush pastures
E. Early dry period
Correct Answer: C. Feeding total mixed rations
Explanation: Feeding high-energy total mixed rations, especially those low in fiber, has been associated with an increased risk of HBS. APHIS+1DAIReXNET+1
Question 3:
What is the most definitive method for diagnosing hemorrhagic bowel syndrome in cattle?
A. Fecal flotation test
B. Abdominal radiography
C. Exploratory laparotomy
D. Blood culture
E. Rectal temperature measurement
Correct Answer: C. Exploratory laparotomy
Explanation: Definitive diagnosis of HBS is achieved through exploratory laparotomy, which reveals characteristic lesions such as intraluminal blood clots and segmental hemorrhagic enteritis. Merck Veterinary Manual
References
- Merck Veterinary Manual. (2021). Intestinal Diseases in CattleMerck Veterinary Manual
- De Jonge, B., et al. (2023). Hemorrhagic bowel syndrome in dairy cattle: Gross, histological, and microbiological characterization. Veterinary Pathology, 60(2), 235–244. PubMed
- Integrated Livestock Management, Colorado State University. Hemorrhagic Bowel Syndrome
- Dairy Cattle Extension. (n.d.). Progress in the Understanding of Hemorrhagic Bowel SyndromeDAIReXNET
- APHIS. (2003). APHIS