Progressive Retinal Atrophy in Dogs

PRA affects the retina, affecting the rod cells which are programmed by hereditary design to die in this condition. It affects both eyes and starts with the loss of the night vision and moves on to the day vision degeneration to effect total blindness. The progression of this disease is gradual, and you may not even be aware that your dog is losing his sight. Because of the gradual deterioration, you dog will adjust to the condition, using other senses to enable him to get around. The eyes will become opaque and cataracts will eventually form on the centre of the eye.

Progressive retinal atrophy (PRA) is a condition that is inherited by your dog and results in total blindness. It affects most dog breeds, and isn’t painful at all.

• Progressive loss of night vision affecting both eyes is usually the first sign of the disease 
• Day vision degeneration occurs over a period of time until total blindness results 
• Eyes begin to have a cloudy look
• The eyes take on a grey colour and have a slight sheen 
• Your dog may bump into walls or into unfamiliar objections
• Reluctance to go down the stairs or jump down steps 
• Decreased color of the pigment of the eyes
• Cataracts form on the retina
• Dilated pupils in both eyes 

Types 

• Progressive retinal atrophy can affect any breed of dog but thankfully is not painful and your dog can adjust extremely well to life without vision 
• It affects most breeds of dogs but is most common in Cocker Spaniels, Labradors, and Poodles
• There are two types of this disease that can affect your dog’s eyesight and health
• Generalized progressive retinal atrophy (GPRA) which is an uncommon form
• Centralized progressive retinal atrophy (CPRA)
• Both forms of PRA are hereditary

• Progressive retinal atrophy is a hereditary condition where the retina is affected by degeneration of the tissue 
• The cause of the disease has been identified as an autosomal recessive gene which must be carried by each parent 
• Even if the parents are not affected by this disease, they can produce puppies that are affected 
• This disease usually affects the vision around the 6 to 8 year mark in a dog’s life

You may notice that your dog is not so adventurous and hesitates about jumping down from any height as he cannot judge the distance anymore. Or you may notice your dog bumps into things around the house, especially if you move the furniture. Usually by the time you notice this change in behavior, the disease has progressed to an advanced stage. As the day vision deteriorates you will notice a white opaqueness forming in the centre of the pupil, this is the cataract forming and further reducing the day vision of your canine friend. 

If you suspect your dog is losing his eyesight, you need to contact your veterinarian who will refer your dog to a veterinary ophthalmologist to perform some tests on the eyes. The usual method to diagnose any abnormalities in your dog’s eye is the electroretinogram (ERG). This test measures the response of the retina to light. This test can prove conclusively that your dog has this disease. Luckily there is no pain for your dog, it will just take a bit of adjusting to getting around and your pet will appreciate your support. Make sure that he can come to no harm outside by shutting the gates to your pool or your property so keep him safe.

There is no treatment that can cure progressive retinal atrophy but if you keep your dog’s environment constant, (keep furniture and objects in the same place) then your dog can adjust amazingly well to this condition. Recent developments in test treatments using antioxidants has been shown to slow the rate of the disease in the retina, although the tests are not conclusive at this time. A similar result in humans using Lutein which is a carotenoid supplement has been discovered but is only useful in the early stages of the disease. 

So far, the substance Lutein hasn’t been trialed on dogs but ongoing research is working towards if not a cure, at least a slowing of the disease. As with many diseases, early detection is better to enable treatment to be effective, and because PRA is slow moving and is not obvious at first, your dog’s condition is usually in an advanced stage when it is diagnosed. The veterinary specialist will not usually remove the cataracts that form over the centre of each eye as it will not assist with the vision, and if removed may cause other problems such as glaucoma to develop.

Management is usually the only option here, as vision loss cannot be reversed. Your dog will adapt to his own environment, although may bump into any new items in the area. If you are taking your dog for a walk, use a lead or a harness on him, which will give your four-legged friend confidence and can guide him where to walk. Treat your dog the way you always have, as they sense changes and may worry.

Ensure that you leave his environment the same (don’t rearrange the furniture) until your pet can adjust to life without vision. Dogs are so adaptable and accept life as it is, they really are amazing. So, show your dog that he is still a valued member of the family and support him as he learns to adjust his other senses such as his hearing and sense of feeling to get around.