Hemeralopia (Dayblindness)

Hemeralopia or "day blindness" is a hereditory disease of the retina involving a partial or complete lack of cone development and eventual degeneration of those which do develope. This leads finally to a retina with only rod photoreceptors, resulting in a classic set of symptoms.

Between two and four months of age, affected dogs usually begin bumping into objects. On very sunny days they demonstrate sight deficits which obviously improve in low light. The condition will gradually worsen.

Because the symptoms are similar to central progressive retinal atrophy (CPRA), dogs suspected of vision abnormalities should be seen be a veterinary opthalmologist. With hemeralopia, no lesions are identifiable through normal opthalmalic examination; whereas, in CPRA ( which is not reported as frequenly in Alaskan Malamutes), characteristic lesions are visible.

Hemeralopia has an autosomal recessive inheritance mode and can be eliminated by sound breeding practices. The attention drawn to this aliment by the AMCA and responsible breeders has significantly reduced it's occurance in the breed. To prevent it's proliferation in the gene pool, the need for constant surveillance of breeding stock is obvious.