Diffuse brain changes on high‐field MRI in a dog with hepatic encephalopathy secondary to portosystemic shunt

Neurological dysfunction secondary to hepatic encephalopathy is commonly observed in dogs with portosystemic shunts. Classical magnetic resonance imaging findings include symmetrical T1‐weighted hyperintensities within the lentiform nuclei, typically attributed to manganese accumulation. Here, we describe a 1‐year‐9‐month‐old, spayed, female pug presented with acute‐onset seizures and progressive neurological deterioration. Diagnostic investigations revealed hyperammonaemia, elevated pre‐prandial bile acids and a congenital left gastro‐azygos portosystemic shunt on computed tomography. High‐field magnetic resonance imaging identified bilateral symmetrical T2‐weighted and T2‐weighted fluid‐attenuated inversion recovery hyperintensities within the grey matter of the frontal, parietal and occipital lobes and cingulate gyrus, consistent with a diffuse encephalopathy. Despite medical management, including lactulose enemas, antiepileptic therapy and intravenous lipid infusion, the patient failed to improve and was euthanased due to progressive neurological decline.