Granulomatous encephalitis in a neurologically impaired goat kid associated with degeneration of Neospora caninum tissue cysts

Congenital Neospora caninum infection was diagnosed in a Saanen goat from a farm in southern Brazil. The kid was unable to nurse and had difficulty ri sing, ataxia, and opistothotonos. The neurologic signs became more severe 3 days after birth, when it was euthanized. No gross lesions were observed a t necropsy. Multifocal infiltrates primarily of mononuclear cells, nodular microgliosis, and perivascular cuffs of lymphocytes, plasma cells, and few neutrophils were observed in the brain, mostly in the cortex and adjacent t o ventricles. Rare multinucleate giant cells were observed adjacent to infl ammatory foci. Several tissue cysts with a thick wall that reacted strongly with polyclonal antiserum to N. caninum were in the cerebral cortex and me dulla oblongata. Lesions were also present in heart, lungs, and liver, but N. caninum tachyzoites were not found. Distinguishing features in this goat kid included neurologic impairment resulting from congenital infection wit h N. caninum and the presence of granulomatous inflammation with rare giant cells associated with degeneration of tissue cysts.