Ultrastructure of retinal pigment epithelial and neural cells in the neuronal ceroid-lipofuscinosis affected Dalmatian dog.

Ubiquitous accumulation of lipopigments, entailing lamellar, fingerprint, and curvilinear bodies in varying cell types of the retina, and, in addition, peculiar circular inclusions within retinal pigment epithelial cells in the retina of two Dalmatian dogs afflicted with neuronal ceroid-lipofuscinosis, emphasize the identity of its retinal ultrastructural pathology to that observed in NCL-affected English setters, while the retinal layers appear largely preserved. The circular inclusions in RPE cells are unique to canine NCL; they are not encountered in human NCL, nor in primary non-NCL retinal dystrophies of other canine species. Their origin and pathogenesis, so far, remain subject to speculation, rather than to convincing explanation.