Clinical signs, diagnostic imaging and histopathology in a dog with granulomatous meningoencephalitis manifested as a polyneuropathy

Abstract

An 11-year-old, female, neutered Labrador retriever with a history of chronic and progressive right hindlimb lameness and facial asymmetry was referred for brain and lumbosacral magnetic resonance imaging and cerebrospinal fluid analysis. Multifocal non-enhancing T2-weighted images of hyperintense lesions were observed in the caudate nuclei and medulla oblongata. The right oculomotor nerve was markedly enlarged and showed marked enhancement on T1-weighted images after contrast injection, and there was diffuse enlargement of the sciatic and femoral nerves in the right hindlimb. Cerebrospinal fluid analysis showed a mixed pleocytosis. Histopathology revealed granulomatous inflammation affecting the brain, oculomotor and pelvic limb nerves, consistent with a diagnosis of granulomatous meningoencephalomyelitis.