Day Blindness in Dogs

Category: Eye
Breeds documented: 5
Published sources: 6

Overview

Bright conditions can make it hard for an affected dog to see, while movement in dim light remains much easier. Day blindness, also called achromatopsia, can result when cone cells in the retina fail to work properly. These cells normally support vision in daylight. Some inherited forms involve CNGB3 gene changes, but not every affected dog has the known variants.

Signs to watch for

Difficulty finding a way around outdoors in bright light
Moving more confidently in dim light
Avoiding bright light or seeming uncomfortable in it

Known CNGB3-related forms often show signs between eight and twelve weeks of age.

When to get help Book a vet visit if daylight vision becomes difficult or bright light seems uncomfortable.

Diagnosis and tests

The eyes can look normal during an ordinary examination despite clear daytime vision problems. Electroretinography, a test of the retina's electrical response to light, can confirm loss of cone function. DNA tests can identify the known CNGB3 forms, but affected Labradors have tested negative for those changes.

Breeds with documented risk

5 breeds

By breed size

3 Medium
2 Large

Labrador RetrieverLarge · Sporting Group
German Shorthaired PointerMedium · Sporting Group
Siberian HuskyMedium · Working Group
Alaskan MalamuteLarge · Working Group
Alaskan HuskyMedium

Inheritance

Not yet known
None of the sources we use states how this is inherited in dogs yet.

We've gathered what published sources say about this condition, so you can talk it through with your vet. It isn't veterinary advice: you and your vet know your dog best.