Also called Cone degeneration this is an inherited disorder affecting several breeds.

The disorder has been identified for the first time in the 1960’s in a strain of inbred Alaskan malamute dogs.

Phenotypically, as well as genetically, characteristics of cone degeneration are similar to the achromatopsia, an inherited disease in human beings.

First symptoms of cone degeneration usually occur after the retinal development is normally completed, which is between 8 and 12 weeks of age in the affected dog.

These symptoms are recognizable only in the day light, and they are day blindness and photophobia.

In dim light, the symptoms are not obvious and vision in dim light remains normal.

After birth, cones develop normally, but with time they lose their function and their inner and outer segments start to degenerate.

This events are followed with gradual loss of cones throughout the animal’s lifetime.