Clinical and imaging features of Pseudomonas aeruginosa ventriculitis with suspected obstructive hydrocephalus in a German Shepherd dog

A 5‐year‐old male neutered German Shepherd dog was evaluated following a seizure for acute and rapidly progressive obtundation, vertical nystagmus and ataxia. Magnetic resonance imaging exhibited marked hydrocephalus in the lateral ventricles with cerebellar herniation through the foramen magnum. In the periventricular tissues, T2‐weighted fluid‐attenuated inversion recovery hyperintensity was present, representing periventricular oedema. The ventricular walls were multifocally thickened and contrast enhancing, indicating ventriculitis. There was mild multifocal asymmetric enhancement of the meninges of the left rostroventral calvarial margin and cervical spinal cord, with cervical syringomyelia. The patient was not able to self‐ventilate and was euthanased within 24 hours of starting supportive treatment. Necropsy findings were consistent with ventriculitis, meningitis, hydrocephalus and cerebellar herniation. A moderate yield of Pseudomonas aeruginosa was detected on cerebrospinal fluid culture and postmortem brain tissue culture.