title: Optic pathway degeneration in Japanese black cattle.
abstract: Degeneration of the optic pathway has been reported in various animal species including cattle. We experienced a case of bilateral optic tract degeneration characterized by severe gliosis in a Japanese black cattle without any obvious visual defects. To evaluate the significance, pathological nature and pathogenesis of the lesions, we examined the optic pathway in 60 cattle (41 Japanese black, 13 Holstein and 6 crossbreed) with or without ocular abnormalities. None of these animals had optic canal stenosis. Degenerative changes with severe gliosis in the optic pathway, which includes the optic nerve, optic chiasm and optic tract, were only observed in 8 Japanese black cattle with or without ocular abnormalities. Furthermore, strong immunoreactivity of glial fibrillary acidic protein was observed in the retinal stratum opticum and ganglion cell layer in all 5 cattle in which the optic pathway lesions could be examined. As etiological research, we also examined whether the concentrations of vitamin A and vitamin B12 or bovine viral diarrhea virus (BVDV) infection was associated with optic pathway degeneration. However, our results suggested that the observed optic pathway degeneration was probably not caused by these factors. These facts indicate the presence of optic pathway degeneration characterized by severe gliosis that has never been reported in cattle without bilateral compressive lesions in the optic pathway or bilateral severe retinal atrophy.
authors.affiliation: Laboratory of Veterinary Pathology, Department of Basic Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Shiori
authors.initials: S
authors.lastname: Chiba
authors.forename: Shingo
authors.initials: S
authors.lastname: Funato
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Horiuchi
authors.forename: Kotaro
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Hisashi
authors.initials: H
authors.lastname: Inokuma
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Furuoka
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000235:genetics / Q000473:pathology*; D005260:Female; D020022:Genetic Predisposition to Disease; D008297:Male; D009900:Optic Nerve / Q000473:pathology*; D065866:Optic Tract / Q000473:pathology*; D012160:Retina / Q000473:pathology*; D014795:Visual Pathways / Q000473:pathology*