2012 by Taylor & Francis Group, LLC. Acute visual loss or blindness is a relatively uncommon, but important, clinical syndrome of dogs and cats. Bumping into walls or inanimate static objects and an inability to recognize moving objects are classic signs of visual loss that typically are noted by owners of animals with bilateral blindness. However, unilateral blindness may be more difficult for owners to recognize. Depending on the aetiology, visual loss initially may be partial or complete. Partial visual loss may progress to complete blindness over days to weeks. Visual loss may be due to a lesion of the retina, optic nerve, optic chiasm, optic tract, lateral geniculate nucleus (LGN), optic radiations or visual cortices. Although the entire visual pathways are part of the CNS, in this chapter they are divided into: Peripheral visual pathways: visual pathways that are shared with the PLR pathways (i.e. retina, optic nerve, optic chiasm, proximal optic tract).
