Torsion of the papillary process of the caudate liver lobe in an American pit bull mix dog.

A 6-year-old castrated male American pit bull mix dog was presented with acute vomiting, lethargy, and abdominal distention. Abdominal radiographs revealed a mass effect in the right cranial abdomen, with regional loss of serosal detail. Abdominal ultrasound and contrast-enhanced computed tomography identified a non-enhancing, malpositioned papillary process of the caudate liver lobe with associated venous thrombosis and surrounding peritoneal effusion. Exploratory laparotomy confirmed a 360° torsion of the papillary process of the caudate liver lobe, necessitating lobectomy. Histopathologic assessment demonstrated hepatic infarction with no evidence of neoplasia, and postoperative recovery was uneventful. Liver lobe torsion is a rare, life-threatening condition in dogs, often presenting with nonspecific gastrointestinal signs. Definitive diagnosis relies on advanced imaging, with contrast-enhanced computed tomography particularly valuable for identifying patterns characteristic of organ torsion. This case highlights the importance of considering liver lobe torsion as a differential diagnosis in dogs with acute abdominal signs and supports the role of timely surgical intervention in achieving favorable outcomes. Key clinical message: Liver lobe torsion, though rare, should be considered in dogs presented with acute gastrointestinal signs and abdominal effusion. Prompt diagnosis using advanced imaging and timely surgical intervention can lead to an excellent prognosis.