Of the RPGRIP1−/− dogs, 51 were retinal degeneration cases affected at various ages of onset (0.3–15.0 y), one was an acquired retinopathy case (sudden acquired retinal degeneration, SARD, age 6.6 y), three had marginally abnormal fundus with apparently normal visual function (2.4–7.2 y), and 23 had apparently normal vision and fundoscopic appearance (3.8–12.4 y). Here, RPGRIP1 is linked to retinal degeneration.