An inherited retinopathy in collies. A light and electron microscopic study

A recessively inherited retinopathy in collies aged 8 to 189 days was studied by light and electron microscopy. The disease is produced when the outer segments of rods and cones fail to develop normally. Retinal pigment epithelial changes found in several litters appeared to form a separate disease entity. We compared the collie retinopathy with other canine models and the collie ectasia syndrome.