Hemorrhagic Bowel Syndrome in Pigs

Hemorrhagic bowel syndrome affects rapidly growing swine 4–6 months old. Pigs die suddenly without evidence of diarrhea; however, on postmortem examination, the small intestine is thin-walled and filled with either clotted or unclotted blood (see hemorrhagic bowel syndrome image, pig). The large intestine usually contains tarry fecal material but no lesions suggestive of swine dysentery, salmonellosis, proliferative enteropathy, or intestinal spirochetosis. The syndrome can be prevented by administration of either bacitracin or chlortetracycline in the feed.

Hemorrhagic bowel syndrome, pig

Image

Hemorrhagic bowel syndrome in a pig, with markedly distended and congested small and large intestines suggestive of torsion with venous infarction; however, no torsion is present at postmortem examination.

Courtesy of the Iowa State University Veterinary Diagnostic Laboratory.

A peracute form of proliferative enteropathy can have similar clinical and gross lesions; however, histological evaluation and PCR assay on intestinal contents will discern the presence or absence of epithelial proliferation and Lawsonia intracellularis.

The cause of hemorrhagic bowel syndrome is unknown. Predisposing factors include vigorous exercise, handling, fighting, piling, or irregular feeding. Highly fermentable rations, particularly if fed in liquid form, can increase the incidence of disease. At postmortem examination, lesions are similar to those of venous infarction secondary to mesenteric torsion; however, no torsion is observed. It has been suggested that the condition could be due to partial torsion or that the torsion is resolved ante mortem.

Diagnosis is by exclusion of other causes of intestinal disease, as noted above, and the histopathological observation of transmural intestinal hemorrhage.