Vomiting After Enterotomy in a Dog with a Foreign Body
A 4-year-old castrated male Labrador (32 kg) is 48 hours post-cellotomy for a linear foreign body anchored at the pylorus and ileum. The surgeon closed the enterotomy in a single simple-interrupted layer of 3-0 PDS. Since recovery the dog has vomited 6 times, is dull, and has a heart rate of 140/min, rectal temperature 39.4 C, and abdominal pain on palpation. Fluid resuscitation with balanced crystalloids is ongoing. Bloodwork shows PCV 54%, total solids 6.8 g/dL, lactate 4.2 mmol/L, and creatinine 2.1 mg/dL (baseline 0.9). Abdominal radiographs show two dilated small intestinal loops with a focal gas pattern but no free gas.
1. What is the most likely diagnosis, and what findings support it over other causes of postoperative vomiting?
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The leading concern is dehiscence/peritonitis at the enterotomy or an anastomotic leak, with early septic peritonitis and possible intestinal obstruction. Supporting features: vomiting beginning 48 h post-op (peak risk window for dehiscence is days 2-5), progressive dullness, fever (39.4 C), tachycardia, abdominal pain, hemoconcentration (PCV 54% with normal-to-high TS suggesting dehydration plus protein loss into the peritoneum), rising creatinine (prerenal azotemia), and hyperlactate (4.2) indicating hypoperfusion. The focal dilated loops with gas could reflect ileus or early obstruction, but the systemic inflammatory signs point to leakage. Less likely alternatives: postoperative ileus alone (usually no fever or marked pain), pancreatitis (possible but less likely to cause this focal gas pattern), or a retained/missed foreign body. Free gas is often absent on radiographs with small-volume leaks, so a negative film does not exclude dehiscence.
2. How would you confirm the diagnosis, and what does each test add?
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Abdominal fluid analysis via abdominocentesis (ideally ultrasound-guided): look for a degenerate neutrophilic exudate, intracellular bacteria, and low glucose/high lactate relative to blood. A fluid glucose more than ~20 mg/dL below serum and fluid lactate above serum strongly supports septic peritonitis. Ultrasound: assess for free fluid, focal wall discontinuity, and loss of intestinal wall layering at the enterotomy. Bloodwork trend: rising lactate and creatinine despite fluids supports ongoing sepsis/hypoperfusion. Exploratory laparotomy is both diagnostic and therapeutic if suspicion is high; do not delay for every test if the dog is deteriorating. A negative tap does not exclude a sealed or focal leak, so clinical trajectory drives the decision.
3. If dehiscence is confirmed at surgery, what intraoperative decisions most affect outcome?
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Key decisions: (1) Resect the failed enterotomy segment rather than simply re-suturing devitalized or inflamed tissue; perform a fresh end-to-end anastomosis with healthy, well-perfused margins and tension-free apposition. (2) Thorough peritoneal lavage with warm sterile saline (several liters) and suction. (3) Obtain culture of peritoneal fluid before antibiotics. (4) Omental coverage of the anastomosis to bolster the repair and provide vascular supply. (5) Avoid unnecessary additional enterotomies; minimize contamination. (6) Consider a feeding tube (e.g., jejunostomy) because early enteral nutrition improves healing, and plan broad-spectrum antibiotics with anaerobic coverage. (7) Close the abdomen primarily if possible; leave open management only if contamination is uncontrolled. Postoperatively, correct hypoproteinemia/hypoalbuminemia risk, monitor lactate and urine output, and maintain analgesia.