Vasculitis in a dog resembling isolated angiitis of the central nervous system in humans

An 1-year-old dog succumbed to a seizure disorder of 18 days duration. At necropsy, an area of hemorrhage and discolored parenchyma was identified in the left pyriform lobe of the brain. Microscopic examination revealed a localized, necrotizing vasculitis with associated cerebral necrosis. Vasculitis was not present in other organs. This presentation is consistent with isolated central nervous system (CNS) angiitis, a rare form of vasculitis in humans.