Dash, R. F.Manso Díaz, GabrielSuarez‐Bonnet, A.Hewetson, M.2026-03-182026-03-182026Dash, R.F., Manso- Diaz, G., Suarez- Bonnet, A. & Hewetson, M. (2026) Duodenal stricture and portal gas accumulation secondary to ulcerative, fibronecrotising duodenitis in a foal. Equine Veterinary Education, 00, 1–6. Available from: https://doi. org/10.1111/eve.700780957-773410.1111/eve.70078https://hdl.handle.net/20.500.14352/134124Author Contributions R. F. Dash: Investigation; writing – original draft; writing – review and editing; resources. G. Manso- Diaz: Investigation; writing – original draft; writing – review and editing; resources. A. Suarez- Bonnet: Investigation; writing – original draft; writing – review and editing; resources. M. Hewetson: Investigation; writing – original draft; writing – review and editing; supervision; resourcesGastroduodenal ulcer disease with secondary stricture formation of the proximal duodenum and portal gas accumulation is described in a neonatal foal. Conventional diagnostics were performed to reach a diagnosis, including gastroscopy, ultrasonography and positive contrast radiography. In addition, a post- mortem CT was acquired with the contrast media in situ. This permitted visualisation of the stricture itself and demonstrated the location to be pyloric and proximal duodenal, which was confirmed on post- mortem examination. Hepatic gas was observed on the initial radiographic and ultrasonographic examination; however, it could not be determined whether this was within the biliary system or portal venous system. CT demonstrated that this gas was within the portal veins. Portal venous gas accumulation has been reported in small animals as a sequela of necrotising gastroenteritis, gastrointestinal ulceration and gastric trauma, but has never been reported in horses. Previously, hepatic gas seen in foals with this presentation was thought to be in the biliary treeengAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/journal article2042-3292https://doi. org/10.1111/eve.70078open access636.09HorseComputed tomographyFoalGastroduodenal ulcerationPortal gasStrictureVeterinaria3109 Ciencias Veterinarias