Spontaneous necrotising encephalitis in a New Zealand White pet rabbit: CT and clinical findings

Abstract This case report details the clinical and imaging findings of a 6.2‐year‐old New Zealand White pet rabbit with spontaneous necrotising encephalitis. Signalment included sialorrhea, difficulty in food prehension, depressed mentation, spastic right facial paralysis, eyelid paralysis of the right eye, proprioception deficit on all limbs, diagonal gate and circling to the right, episodes of rhythmic clonic horizontal head movements and head pressing. CT showed an irregular C‐shaped, ill‐defined, multilocular, peripherally mineralised mass characterised by moderate, heterogeneous and mostly ring‐like contrast enhancement in the right fronto‐parietal region and signs compatible with right otitis media. The 1‐month follow‐up CT scan revealed persistence of the intra‐axial lesion, but the pneumatisation of the right tympanic bulla was normal at that time. After an initial clinical improvement, the patient relapsed and was euthanased. Histopathological examination of the brain revealed severe necrotising encephalitis. The aetiology could not be established; bacterial origin was suspected but not confirmed.