Herniation of Duodenum into the Right Ventral Hepatic Peritoneal Cavity with Groove Formation at the Ventral Hepatic Surface in a 2-Week-Old Chicken

Internal hernia in avian species is very rare. A necropsy of a 2-week-old SPF White Leghorn chicken revealed that a loop of the duodenum and part of the pancreas (4 × 2 × 1 cm) was protruding through the abnormal foramen (2.5 cm in diameter) in the right posthepatic septum into the right ventral hepatic peritoneal cavity. The herniated loop was located underneath the ventral hepatic surface, leaving a groove on the right hepatic lobe (2 × 1.5 × 0.4 cm). The part of the pancreas involved in the hernia was grossly enlarged. Microscopically, a zone of pressure atrophy of hepatic tissue was characterized by crowdedness of hepatocytes with pyknotic nuclei and faint eosinophilic cytoplasm and indistinct narrow sinusoids. The pancreas revealed hypertrophy of the acinar cells with an increase in the secretory granules and basophilic cytoplasm. This is the first report of duodenum herniation into the right ventral hepatic peritoneal cavity resulting in groove formation on the ventral hepatic surface in a 2-week-old chicken.