Progressive retinal atrophy in the Samoyed.

In Samoyeds 2-5 years old, progressive retinal atrophy was evidenced ophthalmoscopically by peripheral tapetal hyperreflectivity and vascular attenuation, with marked generalized retinal thinning and vascular attenuation at 5-8 years. Pupil response remained active until late in the disease. Histologically, early retinal development was normal, with lesion onset paralleling that of ERG abnormalities. Pedigree examination and test-breeding results were compatible with simple autosomal recessive inheritance.