Dog congenital stationary night blindness (CNSB)
Dog congenital stationary night blindness is an inherited eye diasese, that affects Briards. It is characterized by slow progressive retinal degeneration with very early onset of clinical symptoms. Retina is an important part of the eye that collects visual information and sends them to the brain. It is caused by a deletion in RPE65 gene encoding a protein responsible for regeneration of 11-cis retinol in the visual cycle. The mutation is inherited recessively. Affected dogs show a severe impairment of visual function, primarily of night vision, but, in some cases day vision is affected to various degrees, and abnormal electroretinogram. Heterozygous dogs have normal visual function and electroretinogram, but are the disease carriers. When two heterozygous dogs are bred, chances of getting a puppy with the disease are high.
Bechyňová, R., Dostál, J., Stratil, A., Jílek, F., and Horák, P. (2008). Mutation in the RPE65 gene causing hereditary retinal dystrophy in the Briard dogs: Application of a new detection method. Czech Journal of Animal Science 53, 176–179.