Surgical resection of an enteric duplication cyst in a domestic rabbit (Oryctolagus cuniculus)

Background: Congenital enteric duplication cysts are a rare congenital subtype of endodermal duplication. Case Description: A 6-year-old, neutered male domestic rabbit (Oryctolagus cuniculus) presented for an abdominal mass that had been identified by his primary veterinarian on routine physical examination. The mass was initially treated procaine/benzathine benzylpenicillin without improvement in the size of the mass. On presentation to the referral center, physical examination and abdominal ultrasound confirmed a firm, round caudal abdominal mass. Aside from minor changes, bloodwork was unremarkable. The mass was thick-walled and contained hyperechoic structures that were suspected to indicate either gas or mineralization. Differentials for the mass included a mesenteric abscess or an intestinal neoplasm. The rabbit was hospitalized prior to an exploratory laparotomy and mass removal. Exploratory surgery revealed a 5.0 x 4.0 x 3.5 cm abdominal mass that had multiple adhesions to the surrounding small intestines but did not appear to be originating from the intestinal tissue. The adhesions were broken down via blunt dissection and bipolar electrocauterization. The mass was excised and submitted for bacterial culture and histopathology. The culture yielded growth of Escherichia coli and Bacteroides fragilis. Histopathology revealed a presumed congenital enteric cyst. The rabbit recovered well from surgery with supportive care and was discharged two days after the procedure. The animal was doing well at home over 1 year postoperatively. Conclusions and Case Relevance: This report describes successful surgical treatment and long-term survival of a domestic rabbit with an enteric cyst. Enteric cysts should be included in the list of differential diagnoses in a rabbit presenting for an abdominal mass.