Spontaneous Unusual Backflow from Duodenum to Biliary System in a Dog with Pancreatic Abscesses: A Case Study.

Spontaneous duodenobiliary reflux is a rare condition in veterinary medicine, previously documented in only one canine case. We report a second instance in a 3-year-old neutered male Yorkshire Terrier, detected incidentally during a barium contrast study of the gastrointestinal tract (GIT). Multimodal imaging, including radiography, computed tomography (CT), and ultrasonography, confirmed the reflux and identified abscessing pancreatitis as its cause-a previously unreported etiology in dogs. This case expands the understanding of duodenobiliary reflux in canines, identifies abscessing pancreatitis as a novel differential, and demonstrates the diagnostic value of advanced imaging. In conclusion, abscessing pancreatitis should be considered as a potential cause of duodenobiliary reflux in dogs, and the use of multiple imaging modalities is pivotal for accurate diagnosis and management of this unusual condition.