Small intestinal incarceration caused by external herniation can be diagnosed clinically in cattle, but laparotomy is required to confirm internal incarceration.

To describe the clinical, laboratory and ultrasonographic findings, treatment, and outcome of cattle with small intestinal incarceration (SII) through internal and external hernias. The medical records of 85 cattle with SII admitted between January 1, 1987, and December 31, 2019, were retrospectively reviewed. The long-term outcome was determined 2 years after discharge. 85 cattle had herniation of the small intestine through congenital or acquired openings in mesentery or omentum (internal herniation; n = 60) or the abdominal wall (external herniation; 25). The most common findings were little or no feces in the rectum (77 of 85 [90.6%]), reduced or absent intestinal motility (76 of 85 [89.4%]), and hypocalcemia (36 of 44 [81.8%]). Thirteen (15.3%) cattle died or were euthanized without surgery. Of the remaining 72 (84.7%) cattle that underwent surgery, 42 survived the procedure. Overall, 52 of 85 cattle (61.2%; 95% CI, 50% to 72%) did not survive to hospital discharge and 33 (38.8%; 95% CI, 28% to 50%) were discharged alive. Of these, 11 (33.3%; 6 with and 5 without hernias closed completely) were still productive in their respective herds 2 years later. The diagnosis of an incarcerated external hernia is usually straightforward, whereas internal SII necessitates laparotomy or postmortem examination for a definitive diagnosis. Internal herniation should be part of the differential diagnosis in cattle with signs of ileus. Immediate surgical treatment is paramount in cattle with SII.