Abstract
<title>Abstract</title> <p>Background: Gossypiboma is a retained surgical sponge or gauze that is unintentionally left in the body during surgery. Previously, transmural migration has been reported in a limited number of cases involving the jejunum, ileum, cecum, and urinary bladder in veterinary medicine. However, no cases of colonic transmural migration have been described in veterinary patients to date. Case presentation: A 15-year-old spayed female Shih Tzu presented with chronic acute hemorrhagic diarrhea. The dog had undergone ovariohysterectomy 10 months before presentation. Radiography, ultrasonography, and computed tomography revealed two caudal abdominal masses. One mass was located adjacent to the distal jejunum and exhibited a spongiform pattern containing gas. The other mass was associated with the descending colon and extended into the abdominal wall, causing disruption of the colonic wall and leakage of fecal-like contents. Exploratory laparotomy revealed a 4 × 4 surgical sponge retained within the encapsulated mass adjacent to the distal jejunum. Another 4 × 4 surgical sponge was found within the resected descending colonic segment, which firmly adhered to the abdominal wall. Histopathological findings were consistent with transmural migration. The colonic wall was destroyed through its full thickness and perforated with a textile-like foreign body surrounded by pyogranulomatous inflammation. Inflammation was more severe along the serosal aspect than along the mucosa. A culture of the abdominal wall abscess yielded Escherichia coli and Enterococcus faecalis. The dog recovered without complications. Conclusion: To the best of our knowledge, this is the first veterinary clinical report of the transmural migration of a gossypiboma into the descending colon with concurrent abdominal wall abscess formation in a dog.</p>