Free abdominal gas after laparotomy: is it dehiscence?
2-year-old French Bulldog that underwent enterotomy for a foreign body 4 days ago. He is slightly lethargic but eating. The radiograph shows a small amount of free gas between the liver and the diaphragm.
Which statement is correct?
chevron_right Show answer and explanation
A. Free gas confirms dehiscence and requires immediate repeat laparotomy
After laparotomy some residual free gas is expected and may persist for days or weeks. On its own it does not prove dehiscence.
B. Residual gas is always reabsorbed within 24 hours; at 4 days it indicates perforation
False: postoperative gas may take much longer to be reabsorbed. Using such a short window leads to unnecessary surgery.
C. A barium study should be performed to locate the leak
If a leak is suspected, barium is contraindicated: in the peritoneum it causes granulomatous peritonitis and adhesions.
D. The gas may be residual; abdominocentesis with cytology (intracellular bacteria), fluid glucose and lactate is a better guide to dehiscence
Correct. With postoperative free gas, the clinical picture and peritoneal fluid decide: intracellular bacteria, fluid glucose clearly lower than blood glucose or lactate higher than in blood support septic peritonitis. Increasing gas on serial radiographs is also suspicious.
lightbulb Key takeaway
Pneumoperitoneum is normal after recent laparotomy, laparoscopy or abdominocentesis. Without previous surgery, free gas indicates hollow-viscus perforation (or anaerobic infection) and is a surgical emergency. After surgery, judge by the trend in gas volume and by peritoneal fluid analysis.
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.