Severe meningeal fibrinoid vasculitis associated with Theileria taurotragi infection in two short-horned Zebu cattle.

The Authors describe a severe vasculitis with fibrinoid necrosis of the meningeal arteries observed in two brains of indigenous short-horn zebu (Bos indicus) cattle, with bovine cerebral theileriosis (BCT) caused by a tick-transmitted hemoprotozoan, Theileria taurotragi, from Northern Tanzania. In the Author's opinion, the role of T. taurotragi infection in the angiocentric and angiodestructive detected features remains to be evaluated. A possible immunopathologic cancerous mechanism, secondary to the lymphoid deregulation, could be involved. This report suggests further studies to better characterize the lymphoid cell involvement in the pathogenesis of the meningeal vascular lesions by T. taurotragi.

Neurologic disease in a pig.

Three 4-week-old Yorkshire-Hampshire cross piglets from a litter of 9 (7 liveborn) developed convulsions the day of weaning. They were subsequently obtunded, ataxic, and hypermetric and had intention tremors. An affected male pig was presented live for necropsy on day 5 postweaning. This animal was euthanatized and necropsied. No significant grossly visible postmortem lesions were found. Histologic examination of the brain disclosed laminar necrosis of the submeningeal cerebral and cerebellar cortices with replacement by broad sheets of gitter cells. Occasional cerebral and cerebellar leptomeningeal and parenchymal vessels were surrounded by lymphocytes with fewer eosinophils. The morphologic diagnosis was severe multifocal subcortical cerebral and cerebellar laminar necrosis with moderate multifocal lymphocytic and eosinophilic cerebral and cerebellar leptomeningeal and parenchymal perivasculitis. The history and histologic findings are consistent with an etiologic diagnosis of sodium ion intoxication.

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.

Leukoencephalitis and vasculitis with perivascular demyelination in a Weimaraner dog.

Aseptic and noninfectious diseases of the central nervous system are being recognized with increasing frequency. After multiple episodes of neurologic illness, this 7-year-old Weimaraner dog was euthanatized and submitted for postmortem examination. Lesions in the central nervous system were found mainly in the white matter of the cerebral cortex and cervical spinal cord and represented acute and more chronic injury. Necrotizing vasculitis with fibrinoid change and a marked neutrophilic infiltrate dominated the acute lesions. More chronic changes consisted of perivascular demyelination and accumulation of foamy macrophages with positive staining for myelin. An immune-complex (Arthus-type) vasculitis is suspected.