Progressive retinal atrophy (rcd1a-PRA)

Progressive retinal atrophy (PRA) is a leading hereditary cause of blindness in pedigree dogs as is its counterpart retinitis pigmentosa (RP) in humans. PRA shows genetic heterogeneity, as does RP, with several distinct forms already recognized and several more remaining to be investigated. One can distinguish between late onset forms of PRA and early onset (whelp-age) dysplastic changes. The clinical and ophthalmologic signs of both forms are similar. Affected dogs suffer from bilateral Mydriasis, the reflection of the Tapetum lucidum is increased and the retinal vascular network appears atrophic. In the Sloughi breed, dysplasia of cones and rods occurs (a so-called rod cone dysplasia type 1 (rcd1)). The rcd mutation is characterised by an early onset of the disease.