Stargardt Disease

Affected dogs may begin to show signs of decreased vision by 1-2 years of age, including reluctance to go down stairs, bumping into door frames or corners, and difficulty fetching toys. But they are more likely to be diagnosed in middle or advancing age when changes within the eye are more apparent.

Although subtle changes to vision and the retinas may be noted at 1-2 years of age, dogs may not be diagnosed until middle or advanced age when changes are more noticeable.

Stargardt Disease is diagnosed by examining the fundus, or back of the eye. It may be difficult to observe any obvious changes to the retina. But as the disease progresses, there will be mottling of the tapetum (a layer of tissue immediately behind the retina) and thinning of the retinal blood vessels. Changes to the back of the eye are bilateral and symmetrical, helping to distinguish Stargardt Disease from other retinal diseases. If the retinas cannot be evaluated due to other abnormalities, a veterinary ophthalmologist can perform electroretinography (ERG), the definitive test, which measures the electrical activity and, thus, the function of the retinas.

Currently, there is no widespread treatment for Stargardt Disease; however, gene and stem cell therapies are an evolving field.

Talk to your vet about your dog’s Stargardt disease result so you can discuss any signs of vision change and plan monitoring as needed.

Dogs with this condition may be sensitive to bright light and may squint or avoid sunny areas. Offering shaded spaces or tinted car window covers can help make them more comfortable.

Keep your dog’s environment familiar by leaving furniture in consistent locations, using verbal cues or scent markers, and keeping them on a leash in unfamiliar areas.

This variant was first identified in the Labrador Retriever.

Penetrance: Stargardt Disease is inherited in an autosomal recessive manner, meaning a dog must have two copies of the variant to be affected by it.

Gene

ABCA4 Exon 28

Inheritance type

recessive

Clinical category

Ophthalmologic

Citations

1. Makelainen et al 2019
2. Ekesten et al 2022

• Labrador Retriever
• English Labrador Retriever