Pathological findings of hemorrhagic bowel syndrome (HBS) in six dairy cattle cases

Area of Science:

• Veterinary Pathology
• Bovine Medicine
• Gastrointestinal Diseases

Background:

• Hemorrhagic bowel syndrome (HBS) is a significant cause of intestinal obstruction in adult dairy cows.
• Previous descriptions of HBS lesions often involved intraluminal blood clots.
• The precise etiology and pathological characteristics of HBS require further elucidation.

Purpose of the Study:

• To characterize the macroscopic and histopathological findings of intestinal lesions in dairy cows diagnosed with HBS.
• To differentiate the observed pathological features from previously reported HBS descriptions.
• To investigate potential microbial involvement in the pathogenesis of HBS.

Main Methods:

• Macroscopic and histopathological examination of formalin-fixed intestinal tissues from six dairy cows with clinical HBS.
• Detailed analysis of lesion morphology, including intramural hematomas, necrosis, and mucosal integrity.
• Microbiological assessment for the presence of specific bacterial populations within the lesions.

Main Results:

• Pathological examination revealed large intramural hematomas with necrotic foci leading to luminal obstruction.
• Lesions showed detached mucosal layers without intraluminal hemorrhage; hematomas were sometimes covered by intact mucosa.
• Gram-positive, anti-Clostridium antibody-positive short bacilli were identified in hemorrhagic necrotic areas, though their role remains uncertain.

Conclusions:

• The pathological findings in this study, characterized by intramural hematomas, are distinct from prior reports of intraluminal blood clots in HBS.
• The pathogenesis of HBS involves intramural hemorrhage and necrosis, leading to obstruction.
• While Clostridium spp. were detected, their direct causal link to HBS in this context is inconclusive due to their common presence in cattle.