Inclusion and exclusion criteria

Cattle that were at least 1 year of age, had SII in an internal or external hernia at the time of admission, and had a definitive diagnosis of SII via laparotomy or postmortem examination were included. Eighteen cattle with internal SII were excluded because they had been published previously.¹³

Clinical examination

All cattle underwent a standard clinical examination as described.^28,29 The clinical examination procedure was conducted by the first author or under the supervision of the first or second author. The general condition was evaluated by determining the demeanor, behavior, posture including recumbency, appetite, signs of abdominal pain, appearance of the hair coat and muzzle, skin elasticity, position of the eyes in the sockets, and skin surface temperature. General condition was classified as normal or mildly, moderately, or severely abnormal. Cattle with a normal general condition were bright and alert and had normal behavior, posture, and appetite. The general condition was considered mildly abnormal when a mild decrease in alertness and/or mild signs of colic (defined later) were present. A moderate decrease in alertness and sometimes occasional grunting or bruxism, or both, and marked signs of colic were observed in cattle with a moderately abnormal general condition. Cattle with a severely abnormal general condition showed marked apathy and were sometimes recumbent and unable to rise. The rumen was assessed for the degree of fill and number and intensity of contractions. Foreign body tests included the pole test, back grip, and percussion of the abdominal wall over the region of the reticulum with a rubber hammer. Each test was carried out 4 times, and the reaction of the animal was observed each time. A test was considered positive when it elicited a short grunt a minimum of 3 out of 4 times. Ballottement and simultaneous auscultation as well as percussion and simultaneous auscultation of the abdomen on both sides were also carried out. Ballottement and simultaneous auscultation were considered positive when splashing sounds were heard with a stethoscope while the abdominal wall was manually balloted to produce a swinging motion. Percussion and simultaneous auscultation were considered positive when a ringing or ping sound was heard on percussion of the abdominal wall with the handle of a percussion hammer. Rectal examination was done in all cattle. Feces were assessed subjectively for color, consistency, amount, fiber particle length, and any abnormal contents.

The number and severity of signs of colic/abdominal pain were determined as described.^30–32 Signs of mild colic included mild restlessness, shifting of weight in the hind limbs, looking at the flank, lifting the tail, lifting of individual limbs, and tail swishing. Signs of moderate colic were moderate restlessness, brief periods of recumbency, kicking with the hind limbs, arching of the back, and marked tail swishing. Signs of severe colic consisted of marked restlessness, frequent lying down and rising, sweating, grunting, and violent kicking at the abdomen. In addition, the cattle were divided into colic, indolence (dullness), and intoxication phases depending on the stage of illness.^30,31 The colic phase was the initial phase accompanied by the previously described signs of pain. The indolence phase followed the colic phase and was characterized by apathy and markedly abnormal general condition. The last phase was intoxication, in which cattle had tachycardia, congested scleral blood vessels, pale mucous membranes, cool skin surface temperature, sunken eyes, and a dry muzzle.

Laboratory analyses

The collection and examination of blood, urine, and rumen fluid were done as described.³² In brief, the PCV, WBC count, and concentrations of total protein and fibrinogen were analyzed (Contraves AL820 analyzer, F. Hoffmann-La Roche Ltd; or CELL-DYN 3500, Abbott Diagnostics). The concentrations of serum BUN, calcium, inorganic phosphorus, potassium, chloride, bilirubin, and the activities of the enzymes AST and GGT were determined at 37 °C with the use of an automated analyzer (Cobas Mira, Cobas Integra 700, or Cobas Integra 800; F. Hoffmann-La Roche Ltd) and the manufacturer’s reagents (F. Hoffmann-La Roche Ltd) according to the International Federation of Clinical Chemistry and Laboratory Medicine. The venous blood gas analysis was performed with a rapid analyzer (RapidLab 248 analyzer; Siemens). Urine samples were collected by free-flow catch or catheterization in 78 cattle. Urine samples were analyzed with a test strip (Combur 9; F. Hoffmann-La Roche Ltd), and the urine specific gravity was determined with a refractometer (A.KRÜSS Optronic GmbH). The concentration of rumen chloride was determined with a chloride analyzer (MK II Chloride Analyser 926S; Sherwood Scientific).

Ultrasonographic examination

The ultrasonographic examination of the abdomen of 62 cattle was carried out from the right as described,^32,33 and in 6 others, only an abdominal wall hernia was examined. In the 62 cattle undergoing routine abdominal ultrasonography, an abdominal wall hernia was also evaluated ultrasonographically in 13. Briefly, the area from the tuber coxae to the eighth intercostal space and from the transverse processes of the vertebrae to the linea alba on the right side was examined with a 3.5- to 6.5-MHz convex transducer (Logiq 7; GE HealthCare). The appearance of loops of small intestine and their diameter, contents, and motility were assessed. In addition, the appearance, position, and nature of the contents of the cecum and proximal and spiral ansa of the colon and the presence of cecal dilatation were noted.

Diagnosis

A diagnosis of ileus based on the clinical examination was made when the lead signs were characteristic of mechanical ileus, including signs of colic, reduced or absent fecal output, and progressive deterioration in general demeanor.³⁴ When the signs mentioned earlier were accompanied by an external hernia, a diagnosis of SII was made. SII within an internal hernia could not be diagnosed clinically or ultrasonographically and relied on laparotomy or postmortem examination or both. A final diagnosis of both forms of hernia (external and internal) was made during laparotomy or postmortem examination or both.

Surgery

Cattle with internal hernias underwent standing right-flank laparotomy. In cattle that had difficulty standing or that were already recumbent, the right flank laparotomy was done in left lateral recumbency.³² Distal paravertebral anesthesia or proximal paravertebral anesthesia was used at the preference of the surgeon in charge. A 25- to 30-cm incision was made in the midparalumbar fossa, and the muscles, fasciae, and peritoneum were incised with a scalpel. The abdominal cavity was explored in a standardized fashion.^25,35 Internal herniation/incarceration was recognized when distended small intestines entered a rent in the greater omentum, mesentery, or mesometrium. When comorbidities such as intestinal rupture and peritonitis could be ruled out, the herniated intestines were reduced manually by gently pushing them back into the less occupied areas (caudodorsal) of the abdomen. If the cecum or ascending colon was filled with gas, suction was applied with an 18-gauge needle (38-mm length; B. Braun Medical Inc) attached to a sterile Heidelberger extension line (B. Braun Medical Inc), the other end of which was attached to the suction system. The centesis site was sutured with a 2.0 monofilament suture material in a cruciate pattern. When necessary, the defect in the omentum or mesentery through which the bowel had herniated was enlarged manually. In the hernias we observed, the muscles tended to deviate or rupture in different directions, depending on their anatomical course over the body wall (eg, the transverse abdominal muscle ruptured in a dorsoventral direction and the internal oblique muscle in a caudodorsal or cranioventral direction). Therefore, the transverse muscle could be easily split beyond the visible rent in the internal oblique muscle. To ensure complete visualization and subsequent closure of the transverse muscle in this situation, the internal oblique muscle had to be retracted, severed further by manual traction, or incised with scissors. This procedure was modified depending on the situation and the muscles. An attempt was then made to close the defect. When this was not feasible because the area could not be exteriorized, the defect was enlarged sufficiently to reasonably prevent future herniation. Severely compromised intestines were resected and anastomosed after local anesthesia and ligation of the associated mesenteric blood vessels. The devitalized bowel was removed after 2 bowel clamps were applied on each side, and the bowel was resected between them. Single interrupted sutures were placed in the mesenteric and antimesenteric borders, approximately 180° apart. The bowel wall was sutured with a 2-0 USP monofilament absorbable suture material (Covidien Biosyn; Medtronic) in a full-thickness simple continuous suture pattern, interrupted once on each side to avoid a purse-string effect. Protruding mucosa was oversewn with the same monofilament absorbable suture material in a partial thickness Cushing suture pattern. The rent in the mesentery was closed with braided absorbable suture material (Covidien 0 Polysorb or 2 USP; Medtronic). After the surgical procedure, an antibiotic, most commonly amoxicillin (7 mg/kg body weight), was infused into the abdomen in 1 L of isotonic saline solution or polyvinylpyrrolidone. The peritoneum was closed together with the fascia and the transverse abdominal muscle in 1 layer with braided absorbable suture material (Covidien Polysorb TM, 2 USP; Medtronic) in a simple continuous suture pattern. The internal oblique and external oblique abdominal muscles were closed separately with the same suture material in a simple continuous suture pattern. The subcutaneous tissue was adapted with a continuous mattress suture pattern (Covidien Polysorb TM, 0 USP; Medtronic), and the skin was closed with skin staples (Covidien size 35w appose single-use surgical skin stapler; Medtronic).

In cattle with an external hernia, the surgical approach was directly over the hernia and the size of the incision depended on the size of the hernia. Distal paravertebral anesthesia, infiltration anesthesia, or general anesthesia was used depending on the situation and the surgeon’s preference. Herniated intestines with minimal signs of devitalization were simply reduced, which was facilitated by enlarging the hernial ring when necessary. When feasible, devitalized intestines underwent resection and end-to-end anastomosis. Intraperitoneal medication (amoxicillin, 7 mg/kg) was administered, and the abdominal wall was closed. A 12 X 12-inch (30 X 30-cm) Ethicon RML hernia repair mersilene polyester fiber mesh or a 12 X 12-inch (30 X 30-cm) Ethicon vicryl knitted flat mesh was used in some cases. Whenever feasible, the hernia was closed without mesh by use of the techniques and suture materials described for a standard laparotomy closure. If the latter was not possible, the peritoneum, fascia, and muscles were adapted to the greatest extent possible. The mesh was then placed on top of the sutured area, and its 4 corners were fixed to the fascia and internal and external oblique muscles with simple interrupted sutures. The adjacent muscles and fascia were then pulled toward each side of the mesh with braided absorbable suture material (usually Covidien USP 2-0 Polysorb, 1/2 circle atraumatic needle; Medtronic) in a simple continuous suture pattern.

Postoperative treatment

The 33 cattle that were successfully operated and subsequently discharged were fasted for at least 24 hours postoperatively before feeding was gradually resumed. Medical treatment included fluid therapy (33 of 33), antibiotics (33 of 33), analgesics (33 of 33), prokinetic drugs (23 of 33), and electrolyte replacement (17 of 33) as described.³⁰ In Switzerland, where the cattle were treated, all drug products were commercially available and legal for use in cattle as reported to have been administered in the present study.

All cattle received 10 L of a solution containing 50 g of glucose and 9 g of sodium chloride per liter daily for 1 to 7 days (median, 3 days) administered as a slow IV drip via an indwelling jugular vein catheter (Abbocath-T 14G, 14 cm; Abbott) that was maintained for 3 days. Antibiotic treatment included penicillin G procaine (12,000 IU/kg, IM; 24 of 33), amoxicillin (7 mg/kg, IM; 3 of 33), and penicillin G procaine followed by amoxicillin administered IM (6 of 33). Antibiotics were administered for 3 to 4 days (median, 4 days) in most cattle. All cattle received a daily injection of flunixin meglumine (1 mg/kg), ketoprofen (3 mg/kg), or a combination of flunixin meglumine and metamizole (35 mg/kg) given IV for 2 to 6 days (median, 3 days). Prokinetic drugs were used in 23 cattle for a duration of 2 to 15 days (median, 4 days). Two cows received neostigmine (40 to 45 mg in 10 L of a solution containing 50 g of glucose and 9 g of sodium chloride per liter) administered via continuous drip infusion over 24 hours, and 21 received IM metoclopramide (30 mg), usually 7 to 9 at 8-hour intervals, before its use in farm animals was discontinued in Switzerland. Seven cows with hypocalcemia (calcium < 2.0 mmol/L) received 500 mL of 40% calcium borogluconate IV. Hypokalemia (potassium < 4.0 mmol/L) in 15 cattle was treated with daily oral doses of 60 to 100 g of potassium chloride until normokalemia occurred. One cow with hypophosphatemia (inorganic phosphorus < 1.0 mmol/L) was treated with 350 g of sodium dihydrogen phosphate PO.

Euthanasia/slaughter and postmortem examination

Cattle were euthanized using pentobarbital (80 mg/kg, IV) or, in earlier years, sent to the slaughter facility of the Veterinary Hospital (the meat was used for zoo-animal feeding) during or after the initial examination when the owner did not consent to surgery. Cattle were euthanized intraoperatively when severe lesions including ruptured intestines, fibrinous peritonitis, or hemorrhagic infarction were seen or complications occurred, including becoming recumbent on the right side during surgery with exteriorization and subsequent contamination of the intestines. Cattle were also euthanized after surgery when the clinical condition deteriorated. All cattle that died or were euthanized underwent postmortem examination, whereas in slaughtered cattle, only the internal organs were inspected.

Statistical analysis

The statistical analysis was performed via commercially available software (SPSS Statistics, version 26.0; IBM Corp) as described recently.²⁹ Data are reported as numbers, percentages, means, SDs, medians, and 95% CIs for means, medians, and percentages. The 95% CI for the percentages was calculated with an online program (sample size calculators for designing clinical research).³⁶ Frequencies were determined for all variables, and the Shapiro-Wilk test was used to test the data for normality. Means ± SD were calculated for normal data and medians for nonnormal data. In addition, the 95% CIs were calculated for the means and medians. The variables heart rate and rectal temperature over time (days 0 to 7) were analyzed with the general linear model, choosing ANOVA with repeated measures and replacing polynomial contrasts with difference. Differences in nominal data between external and internal hernia data (in terms of whether the surgery could be completed successfully and whether the hernias could be closed completely) were analyzed with the χ² test. A value of P < .05 was considered significant.

Cattle and history

Eighty-five cattle fulfilled the inclusion criteria; 60 had internal and 25 had external SII. Supplementary Table S1 outlines the sex, age, breed, and pregnancy status of the cattle and the history of the disease course. The signalment, location of the hernia, treatment, and outcome of each cattle are shown in Supplementary Table S2. Treatment and outcome are summarized in Figure 1.

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Treatment flowchart (death/euthanasia, surgery, discharge) for 85 cattle with small intestinal incarceration within external and internal hernias. Retrospective study of the medical records of cattle admitted to the Department of Farm Animals, University of Zurich, from 1987 to 2019.

Citation: Journal of the American Veterinary Medical Association 2024; 10.2460/javma.24.01.0002

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General condition, vital signs, abdominal contour, and signs of pain

The general condition was mildly to severely abnormal in all cattle (Table 1), and 3 of 85 cows (3.5%) were recumbent upon admission. The most common abnormal vital signs in the initial examination were lower-than-normal rectal temperature (60.7% [51 of 84]), tachycardia (51.8% [44 of 85]), and tachypnea (42.4% [36 of 85]). Fifteen of 85 cattle (17.6%) had bilateral abdominal distension, and all 25 cattle with external hernias had a prominent abdominal bulge (Figure 2). Nine hernias were on the left side, 16 on the right side, 14 in the flank, 7 cranial to the udder, and 4 in the inguinal area. The size of the hernias ranged from 8 X 8 cm to 25 X 25 cm.

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A large bulge in the lower left flank of a Braunvieh cow in which postmortem examination revealed an incarcerated small intestinal hernia possibly caused by a horn injury (A) and postmortem findings in the same cow. The prolapsed small intestines are dilated and have blue discoloration (B). Hernial ring in the abdominal wall after removal of the intestines (C). Retrospective study described in Figure 1.

Citation: Journal of the American Veterinary Medical Association 2024; 10.2460/javma.24.01.0002

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Twenty-five of 85 cattle (29.4%) had 1 or 2 nonspecific signs of pain (Table 2). Thirty-three of 85 cattle (38.8%) were in the colic phase (abdominal pain). These included lordosis, treading, kicking, restlessness, lying down and rising, and sweating. The cattle with colic had 1 to 4 signs of abdominal pain. These were assessed as mild to severe. Thirty-eight of 85 cattle (44.7%) were in the indolence phase (dullness phase) and 14 (16.5%) were in the intoxication phase at the time of admission. In addition, 56.5% (48 of 85) of the cattle had a tense abdominal wall and 2.4% (2 of 85) had an arched back.

Digestive tract abnormalities

The digestive tract abnormalities are listed in Table 3. Rumen motility was reduced or absent in 98.8% (84 of 85) and intestinal motility in 89.4% (76 of 85) of all cattle. Ballottement and/or percussion and simultaneous auscultation on the right side of the abdomen were positive in 57.6% (49 of 85) of the cattle. Transrectal palpation revealed dilated loops of small intestines and a distended rumen in 38.8% (33 of 85). The fecal output was reduced or absent in 90.6% (77 of 85) of the cattle. In a few cattle, the feces were dark to black and included mucus, blood, and fibrin.

Other clinical findings

Other clinical findings were reduced skin surface temperature on the rump (< 37 °C; 74.1% [63 of 85]), reduced skin turgor (tenting of pinched skin lasting > 2 seconds; 60.7% [51 of 85]), sunken eyes (51.8% [44 of 85]), prolonged capillary refill time (> 2 seconds; 50.0% [41 of 82]), moderate to severe scleral injection (45.2% [38 of 84]), dry and cool muzzle (43.5% [37 of 85]), pale oral mucosa (25.9% [22 of 85]), and ammonia-like or otherwise foul breath (23.5% [20 of 85]).

Urinalysis

The most common findings were aciduria (pH < 7.0; 38.2% [29 of 76]), hemoglobinuria/hematuria (26.9% [21 of 78]), and glucosuria (25.6% [20 of 78]).

Laboratory findings

The laboratory findings are listed in Supplementary Table S3. Hemoconcentration occurred in 70.6% (60 of 85) of the cattle with a concomitant increase in serum urea concentration (azotemia) in 61.4% (51 of 83). Electrolyte abnormalities included hypocalcemia (81.8% [36 of 44]), hypokalemia (72.6% [61 of 84]), hypochloremia (49.4% [41 of 83]), hypophosphatemia (20.9% [7 of 43]), and hypermagnesemia (70.4% [31 of 44]). Metabolic alkalosis was diagnosed on the basis of an increase in blood pH in 27.7% (18 of 65), increase in bicarbonate concentration in 33.8% (22 of 65), and positive base excess in 63.1% (41 of 65) of the cattle.

Ultrasonographic findings

The principal findings were dilated loops of small intestines (92.6% [63 of 68]), subjectively reduced or absent small intestinal motility (95.2% [59 of 62]), and fluid in the abdomen (48.5% [33 of 68]; Supplementary Table S4). The largest diameter of the dilated small intestine (median) was on average 5.4 cm (95% CI, 5.0 to 5.6 cm). Empty poststenotic loops of small intestines were seen in 8.8% (6 of 68) of the cattle. Internal hernias could not be visualized, whereas small intestines could be seen in 17 of the 19 external hernias that were scanned (Figure 3); fluid and/or fibrin between intestinal loops were seen in 10 of the latter. Ultrasonographically, fibrin appeared as irregularly shaped echogenic masses or strands between the intestinal loops. Abomasal dilatation, characterized by a subjectively dilated abomasum filled with hypoechogenic ingesta and fluid, was diagnosed in 19.1% of the cattle. The abomasal folds appeared as thin, echogenic, wavy structures.

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Ultrasonographic images of the abdomen and an external hernia in a 2.75-year-old Swiss Fleckvieh cow. A bulge in the left flank cranial to the udder occurred 1 day before referral to our clinic. The cow had multiple skin abrasions, mild colic, anorexia, increased periods of recumbency, no fecal output, and tachycardia (108 beats/min). The cow had been pastured with 35 other cows and likely suffered a horn injury. The right flank (A) and the bulge (B) were examined via ultrasonography using a convex transducer. A—Multiple dilated loops of small intestine with a diameter of 5.5 cm and no motility were seen in the right flank. B—The bulge was attributable to the herniated small intestine located immediately under the skin. The intestinal wall was markedly thickened and was surrounded by hypoechogenic fluid. Postmortem examination confirmed the tentative diagnosis of small intestinal incarceration. Retrospective study described in Figure 1.

Citation: Journal of the American Veterinary Medical Association 2024; 10.2460/javma.24.01.0002

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Comorbidities

One or several comorbidities were diagnosed in 22.4% (19 of 85) of the cattle including fatty liver syndrome (n = 3); mastitis (3); vaginitis (1); abscess of the perimetrium (1), reticulum (1), or liver (1); cecal dilatation (1); perforated reticular (1) or abomasal ulcer (1); sole ulcer (1); keratitis (1); endometritis (1); calving trauma (1); solar dermatitis (1); and abortion (1).

Treatment and outcome

Twelve of the 85 cattle died during or immediately after the initial examination or were euthanized because of a grave prognosis or because the owners did not consent to surgery (Figure 1). One cow with an incarcerated external hernia that was erroneously diagnosed as phlegmon caused by a horn injury died after medical treatment. Seventy-two cattle were operated, and 30 of these were euthanized intraoperatively. Of the 42 cattle in which the surgery was completed, 9 died or were euthanized postoperatively because of worsening condition, and 33 (7 of 25 with external hernias and 26 of 60 with internal hernias) were discharged after successful postoperative treatment. Of the 9 nonsurviving cattle, 1 was euthanized on the day of surgery and the remainder died or were euthanized on days 1 to 7 (median, 2 days) after surgery. Overall, 61.2% (52 of 85; 95% CI, 50% to 72%) of the cattle did not survive and 38.8% (33 of 85; 95% CI, 28% to 50%) were discharged.

Surgical findings and intraoperative complications

Of the 72 operated cattle, 59 were standing, 3 were sedated and recumbent, and 7 underwent general anesthesia during surgery. In the remaining 3, surgery was started with the animal standing and finished in sternal or lateral recumbency because the cow suddenly became recumbent.

The 60 cattle with internal hernias underwent right flank laparotomy, which was supplemented in 1 cow with an additional right paramedian approach to facilitate access to the herniated intestines. The 60 internal hernias included hernias in the greater omentum (38 of 60), mesojejunum (19 of 60), mesoduodenum (1 of 60), and mesometrium (2 of 60). Of 38 internal hernias into the greater omentum, only the visceral layer of the greater omentum was involved in 34 cattle; therefore, the incarcerated intestines were located in the omental bursa. In 4 cattle, the intestines had herniated through the visceral and parietal layers of the greater omentum and the incarcerated small intestines were located immediately adjacent to the peritoneum. The size of the hernial ring ranged from 2 to 100 cm, and the length of the incarcerated intestines ranged from 12 cm to 10 m. Of the 60 cattle with internal hernias, 52 had 1, 6 had 2, and 2 had 3 hernias because the omentum was torn in different locations.

In the 12 operated cattle with external hernias, the surgical approach was directly over the hernia. Two of the 12 cattle underwent laparotomy first, but because the incarceration could not be reduced, they were euthanized. Seven of the operated hernias were on the left side and 5 were on the right. They were located distal to the paralumbar fossa and cranial to the flank fold (10 of 12) or caudal to the last rib (2 of 12). Surgery was done with distal paravertebral anesthesia (4 of 12), local infiltration of anesthetic (1 of 12), or general anesthesia (inhalation with halothane or isoflurane, 6 of 12; IV xylazine/ketamine, 1 of 12). The size of the hernial rings varied from 7 to 25 cm, and the length of the prolapsed intestines ranged from 10 cm to 10 m. When required, the hernial ring was enlarged to facilitate reduction. This was achieved manually or, when this was not possible, with blunt-blunt surgical scissors. A mesh was used in 3 cows (vicryl; Johnson & Johnson [in 2 cows]; mersilene, Ethicon [in 1 cow]) for closure of the hernial ring, and 4 were sutured with a continuous suture pattern.

The cattle with external and internal hernias did not differ significantly in terms of whether the surgery could be completed successfully (68.8% [11 of 16] vs 55.4% [31 of 56]; difference P = .34; χ² = 0.9), but significantly more of the external hernias could be closed completely (90.9% [10 of 11]) compared with internal hernias (41.9% [13 of 31]; difference P = .02; χ² = 7.9). Two (6.5% [2 of 31]) of the internal hernias could be partially closed, whereas all other hernias (9.1% [1 of 11 external hernias] and 51.6% [16 of 31 internal hernias]) could not be closed.

In 92.9% (79 of 85) of all cattle, only the small intestines had signs of devitalization, and in 7.1% (6 of 85), the large intestines were also involved (these numbers include the 4 nonoperated animals in which the diagnosis was confirmed during postmortem examination). The degree of intestinal devitalization was slight (discoloration of some sections of the intestine was seen but intestinal texture was normal) to moderate (the intestinal wall was more fragile than normal and diffusely dark red) in 28.2% (24 of 85). The remaining 35.3% (30 of 85) had severe intestinal devitalization characterized by black discoloration and what appeared to be necrosis of the incarcerated intestines. Severe intestinal changes accompanied by peritonitis occurred in 18.8% (16 of 85) of the cattle. In 17.7% (15 of 85), the severity of the intestinal changes had not been recorded. Other pathological changes were fibrin deposits between the intestines in 9 cattle, intestinal rupture in 5, liver abscesses in 3, adhesions in 2, and cecal dilatation in 1 cow. To summarize, in 66.7% (28 of 42) of the cattle in which the surgery was completed, reduction of the incarcerated intestines was all that was required, whereas in the remaining 33.3% (14 of 42), resection of parts of the intestines was necessary. One cow with an intestinal hernia in the greater omentum required a second surgery 6 days later because part of the damaged jejunum was no longer patent. After resection of 2 m of jejunum, the heifer made a full recovery.

Short-term outcome of the 42 cattle in which surgery was completed

Nine cattle died or were euthanized within 7 days (median, 2 days) of surgery because their condition became progressively worse (Figure 1). The health status of the remaining 33 cattle returned to normal within 1 to 16 days (median, 2.0 days) after surgery. With 1 exception, appetite normalized within 1 to 16 days (median, 3 days; in cow No. 8, appetite returned to normal after discharge from our clinic). Defecation normalized within 1 to 17 days (median, 3 days). The median rectal temperature of the 33 surviving cattle increased from 38.4 °C on the day of admission to 38.7 °C 7 days later (P = .25), and the median heart rate ranged from 72 to 80 beats/min during the same period (P = .46). Thirty-three cattle were discharged within 5 to 22 days (median, 6 days) after surgery. The health status of the discharged cattle was considered good in 28 and moderate in 5.

Postmortem findings

All hernias were confirmed at postmortem examination (Figure 2). One of the cows with a mesometrial hernia had a uterine abscess. Sixteen of 52 cattle had generalized peritonitis and 5 had localized peritonitis, 4 had ruptured intestines and 3 had multiple abomasal ulcers. One cow was tentatively diagnosed with postoperative paralytic ileus (dilated and ingesta-filled intestines with no mechanical obstruction). Based on the intraoperative and postmortem findings, the jejunum was affected in 72 cattle, the duodenum and ileum in 1 cow each, and multiple small intestinal segments in 9 cattle. No information was available for the remaining 2 cattle.

Long-term outcome of the discharged cattle

The long-term outcome was determined 2 years after discharge via telephone interview. Of the 33 (38.8%) discharged cattle, milk production and reproductive performance were good in 11. The hernia had been closed completely in 6 of these and left open in the remaining 5. Three cows had been slaughtered because of recurrence of the hernia (the hernia had not been closed in 2 cows) and 12 others because of economic or other health reasons. The outcome was not known for the remaining 5 cattle.

Final diagnoses

On the basis of surgical and/or postmortem findings, ileus attributable to SII in an external hernia was diagnosed in 29.4% (25 of 85) and ileus attributable to SII in an internal hernia in 70.6% (60 of 85) of the cattle. The latter included hernias in the greater omentum (38 of 60), mesojejunum (19 of 60), mesoduodenum (1 of 60), and mesometrium (2 of 60). With the exception of 1 cow, external hernia was definitively diagnosed on the basis of the clinical findings (signs of ileus with an abdominal protrusion). In all the cattle with internal hernia, laparotomy was required for a diagnosis.