What Is Progressive Retinal Atrophy in Dogs? Symptoms and Types

Also known as progressive retinal atrophy, or PRA, this eye disease affects the retina in both eyes. The retina is the part of the eye responsible for capturing images and sending them to the brain.

Any damage to it will affect the dog's normal vision. There are different forms this atrophy can take. Unfortunately, it's an incurable condition. Sooner or later, the dog will lose its sight. Want to know all the details about this condition?

What Is Progressive Retinal Atrophy?

Progressive retinal atrophy is a disease in which the retinal cells in both eyes are destroyed. This process results in blindness, since the images captured by the eye can no longer reach the brain.

There are different types of retinal atrophy, for example the early-onset slow-progression type, the early-onset rapid-progression type, the late-onset type, the sudden-acquired type, or the central type.

Which Dogs Get Progressive Retinal Atrophy?

This condition has been described in numerous breeds. As a curious fact, the first case was in the Gordon Setter, in 1911. It's considered a hereditary disease, transmitted through an autosomal recessive gene.

This means that, for the condition to pass from parents to offspring, both parents need to carry copies of the damaged gene. There can be asymptomatic carriers.

How to Tell If My Dog Has Progressive Retinal Atrophy? Symptoms

The first symptom pointing to this disease is loss of night vision. We'll notice this because the dog won't walk confidently if we take it out for a walk once it's already dark, or before dawn.

Also, if it's in a dark room, we may notice it hesitates to get on or off sofas or beds, or bumps into furniture. The disease will keep progressing, so we'll notice more and more difficulties related to vision loss. Behavioral changes will follow, due to this shortfall.

For example, it's common for the dog to have trouble going down stairs. Either way, these are signs that can go unnoticed for quite a while, until the blindness is already very advanced and it becomes obvious the dog has stopped seeing. We may notice dilated pupils, since they no longer react to light. Cataracts sometimes develop too.

• Symptoms and treatment of cataracts in dogs

Symptoms of Early-Onset, Slow-Progression Retinal Atrophy

In this case, affected dogs lose their night vision over the course of their first year of life. However, they retain proper daytime vision for a year or more. This condition affects breeds such as the Akita, Miniature Schnauzer, Dachshund, or Gordon Setter more.

Symptoms of Early-Onset, Rapid-Progression Retinal Atrophy

Unlike the previous type, with this atrophy, vision damage shows up during the first year of life and progresses very quickly. Within a matter of months, blindness is already complete. Affected breeds notably include the Collie, Irish Setter, and Cardigan Welsh Corgi.

Symptoms of Late-Onset Retinal Atrophy

This condition appears in dogs over two years old, who end up completely blind before turning four. Breeds affected by this type of atrophy include the Afghan Hound, Border Collie, Cocker Spaniel, and Labrador Retriever.

Symptoms of Sudden-Acquired Retinal Atrophy

This is a presentation of atrophy more common in females aged between six and fourteen years. The atrophy progresses so fast that, within hours or, at most, days, vision is completely lost. In this case, the cause of the disease is unknown.

Symptoms of Central Progressive Retinal Atrophy

This condition, known as CPRA, is less common than PRA. It appears in older dogs. The cells at the center of the retina are affected, hence its name. It's more common in breeds such as the Golden Retriever, Border Collie, or Smooth Collie. The affected area in this type of atrophy is the one that gives the dog its sharpest vision.

As a result, still objects under bright light can't be seen. However, the dog can still make out moving objects, since these are picked up by the more peripheral part of the retina. That said, as the disease progresses, vision worsens. But it rarely results in complete blindness.

What Is the Treatment for Progressive Retinal Atrophy?

Unfortunately, there's no treatment for this condition. But it's important that, at the slightest suspicion of atrophy, we see a veterinary ophthalmologist. They'll examine the retina to confirm the disease. Specific tests are usually needed, such as ocular ultrasound or electroretinography.

That's why it's important to contact a professional. They may prescribe treatment to slow the disease's progression. Sometimes surgery for the cataracts that develop is needed, although the procedure won't influence the blindness.

Dogs usually adapt to vision loss, and it's up to us to make the effort to make everyday life easier for them. As a preventive measure, dogs with the disease or a high risk of carrying it shouldn't be bred. In pedigree dogs, this information should be documented and available.

Bibliography Carlson and Giffin. 2002. Manual práctico de veterinaria canina. Madrid. Editorial el Drac.