Electroretinographic evaluation of Papillons with and without hereditary retinal degeneration

Objective-To evaluate the function of the outer retina in Papillons with and without hereditary retinal degeneration.Animals-45 Papillons, median age 1.7 (range, 0.8 to 5.1) years.Procedure-Complete physical and ophthalmic examinations were done prior to performing electroretinography under general anesthesia. Full-field electroretinograms (ERG) were recorded, using a special-purpose computer system. Eleven specific ERG responses were recorded, graphed, and evaluated, using age-matched Papillons.Results-Severely decreased retinal function was detected in 8 Papillons. The youngest affected dog was 1.2 years old. in affected dogs, amplitudes of responses mainly originating from the rod system were severely decreased, compared with those originating from the cone system.Conclusions-Papillons represent another breed of dog affected by a hereditary photoreceptor degeneration that can be detected at an early age by using ERG. A reliable age for diagnosis using ERG is considered to be 1.5 years,Clinical Relevance-Thorough and precise ERG procedures and protocols are needed to reliably obtain an early diagnosis of progressive retinal atrophy.