Golden Retriever Training: Sep 14, PRA In Dogs -- Progressive Retinal Atrophy

PRA in dogs is the name given to a group of hereditary eye diseases, most of which result in blindness.

Technically known as Progressive Retinal Atrophy, it was first recognized in Gordon Setters in Europe in 1911. Since then, it's been documented in over 100 breeds, and mixed breeds as well. Fortunately, PRA is relatively rare in Golden Retrievers.

PRA causes the retina to deteriorate over time, until a dog goes completely blind.

It always affects both eyes, but isn't painful.

Let's take a quick refresher course in eye anatomy.

The retina is the tissue lining the back wall of the inside of the eye.

It receives the light gathered and focused by the other eye structures.

It basically converts the light into electrical signals.

Then the optic nerve (in the brain) interprets the signals as vision.

Here's the bottom line: No retina = no vision.

PRA begins with night blindness, followed by gradual loss of day vision and, eventually, total sightlessness.

Golden Retriever There are two groupings of PRA--early onset and late onset.

In early onset PRA, poor vision in low light can be detected shortly after birth.

Total blindness usually occurs in 1 to 5 years.

In late onset forms, night blindness occurs when a dog is 1 to 5 years old.

The condition progresses to total blindness anytime after 3 years of age.

With PRA, the outward appearance of the eye is usually normal. There is no redness, excess tearing, or squinting.

Owners may notice their Golden Retriever being reluctant to go down stairs or down a dark hallway. This is typical night blindness behavior.

Many times, a dog may be so good at adapting to his decreasing sight that the owners are clueless until their dog has an eye exam.

As a dog's vision deteriorates, his pupils dilate wider as they try to gather more light, causing a noticeable "shine" to his eyes.

Dogs with PRA can also develop cataracts as the disease progresses.

Cataract surgery would never be done, of course, as it wouldn't help the dog to see.

However, cataracts can cause pain and damage to the eye.

So if your dog's eyes start looking cloudy, contact your veterinarian as soon as possible.

Cataract eye drops can provide some relief.

A veterinary ophthalmologist can diagnose PRA by dilating a dog's pupils with eye drops and then examining the eyes with an ophthalmoscope.

Golden Retriever The exam takes less than five minutes and the cost usually ranges from $20 to $75.

Many dog clubs offer eye-screening clinics in association with dog events.

Eye exams at these clinics are generally the most affordable.

If an eye exam detects retinal changes potentially associated with PRA, a more sensitive test--an electroretinograph (ERG)--can be done to confirm that the dog has PRA. An ERG is so sensitive that it can detect the presence of PRA long before it can be seen by clinical examination.

Unfortunately, there is no treatment for PRA. Dogs with most types of PRA will eventually become blind.

However, some experts believe that oral antioxidant nutritional therapy for retinal health may help slow the deterioration of the retina to "buy some time" before the blindness inevitably happens.

Since the cause of PRA is a "bad" gene, the only way to prevent the disease is to diagnose it early enough to avoid passing it along to future generations.

Researchers have come up with a DNA blood test to determine if dogs are affected with PRA, are carriers for PRA, or don't have the PRA gene at all.

Unfortunately, this test isn't yet available for all breeds. Hopefully, DNA testing for all breeds will be coming along in the future.

In the meantime, the best option for both breeders and buyers is regular eye checks, and honest disclosure of the problem when diagnosed.

PRA carriers are actually just as likely to be healthy as their normal, non-affected siblings. They'll make great pets, but should be spayed or neutered to keep the PRA gene from being passed along.

Dogs are remarkably adaptable to progressive blindness, and usually navigate their home turf with ease. They'll get around great unless you rearrange the furniture or take them into unfamiliar territory.

It's important to understand that dogs with PRA are happy dogs. Their eyes don't hurt, and their slow loss of vision gives them time to adapt quite successfully.

From your dog's point of view, life continues to be great. You're still nearby, and there are still lots of great smells in his world!