Necrotizing cerebellitis due to Neospora caninum infection in an old dog.

A severe, necrotizing, non-suppurative inflammation of the cerebellum associated with Neospora caninum infection was identified in a 14-year-old male Labrador Retriever. On presentation, clinical signs included mild depression and head tremor, marked ataxia of both thoracic and pelvic limbs, and abnormal postural reactions. In the central nervous system, inflammatory lesions were mainly restricted to the cerebellar leptomeninges and cerebellar cortex, which appeared necrotic and atrophic. Protozoal organisms were positively stained with an anti-N. caninum antibody in an immunohistochemical procedure.