Progressive retinal atrophy early-onset (eo-PRA)

Canine progressive retinal atrophies (PRA) are genetically heterogeneous diseases characterized by retinal degeneration and subsequent blindness. While there are PRA mutations that are shared by multiple breeds, many seem to be private to a single breed or are found in breeds sharing similar ancestral backgrounds. Typical signs found by ophthalmoscopic examination are widespread tapetal hyper-reflectivity and retinal vascular attenuation. Genetic testing complements clinical eye examinations with the advantage of detecting known PRA mutations before breeding age or before clinical signs present.
Besides to the late-onset prcd-PRA form, the so-called early-onset-PRA (eo-PRA) could be found at the breeds Portuguese Water Dog and Spanish Water Dog. Owners of eo-PRA affected dogs reported of first vision problems at the age of 1.5 years, while the dogs show significant loss of vision at the age of 4.5 years. The eo-PRA is caused by a variant of the PDE6B gene and is inherited in an autosomal-recessive manner. At this PRA-from, the age of ophthalmoscopic diagnosis ranges form 1.5-4.5 years, but in most cases after the first noticing changes in the dog’s vision have already occurred.