Day Blindness

What are the signs & symptoms that develop in affected dogs?

Affected dogs may blink repeatedly in daylight, shake their heads, or seek out areas with dimmer light. Affected puppies may bump into objects that unaffected puppies easily avoid, and dogs may be fearful or aggressive in unfamiliar settings.

When do signs and symptoms develop?

Affected dogs develop day blindness and photophobia between eight and 12 weeks of age. Normal cone function can be detected by electroretinography (ERG) in very young cd-affected pups but begins to fail at six to 12 weeks of age. While cone function is absent in mature day blind dogs, rod photoreceptors remain functionally and structurally normal throughout the dog's life.

How do vets diagnose this condition?

Throughout their life, this variant doesn’t result in changes to an affected dog’s retina upon physical examination. Instead, definitive diagnosis of photoreceptor dysfunction is by ERG, which records the electrical potentials of the retina in response to a light stimulus. Referral to a veterinary ophthalmologist may be needed for a definitive diagnosis.

How is this condition treated?

There is currently no treatment for cone degeneration. However, gene therapy is an evolving field. In humans, deeply tinted glasses are used to help manage the symptoms.

What actions should I take if my dog is affected?

• Help affected dogs navigate their homes and the outside world by keeping your furniture in the same location, adjusting light exposure, making sure they are on a leash when in unfamiliar territory, and training them to understand verbal commands.