RHO-related progressive retinal atrophy is an inherited eye disorder described in the English Mastiff, transmitted in an autosomal dominant manner. In carrier dogs, rod-mediated vision may remain normal during the first few months, before retinal degeneration generally becomes evident between 12 and 18 months of age. The disease is also characterized by abnormally slow recovery of photoreceptor function after light exposure, with more severe signs reported in homozygous dogs.
