Progressive Retinal Atrophy was first found in the Gordon Setter in Sweden in 1911. Irish Setter was the first breed to be involved in the United Kingdom following which there have been reports of the disease in many other breeds of dog. The precise mode of inheritance has been confirmed to be a recessive gene most likely in 14 breeds.

What is Progressive Retinal Atrophy?
Progressive Retinal Atrophy also known as “progressive retinal degeneration” is an inherited disease of the retina, in which the photoreceptor cells of the retina are degenerated, first causing night blindness and gradually leading to complete blindness. The PRA affects both eyes simultaneously and there is no known cure for this disease yet. The time frame until the dog is blind varies considerably from dog to dog. Usually, however, complete blindness occurs within one year of diagnosis.

Progressive Retinal Atrophy
Right side: Normal Eye                      Left Side: PRA Effected 

What breeds are prone to Progressive Retinal Atrophy?
PRA occurs in most dogs both of pure and mixed breed. It is recessively inherited in all breeds studied, with the following exceptions: PRA is dominantly inherited in Old English Mastiffs and Bullmastiffs, and PRA is commonly found in male dogs in the Siberian husky and Samoyed breeds.

What causes Progressive Retinal Atrophy?
Most forms of PRA are inherited in an autosomal recessive manner, although both X-linked and dominant forms are recognized.

What are the signs of Progressive Retinal Atrophy?
The below mentioned signs can be indicative of PRA

  • Dilated pupils and a glow from the eyes
  • The first sign of any type of PRA is night blindness. The dog will be reluctant or afraid of walking into any dark area, indoors or out.

How is Progressive Retinal Atrophy diagnosed?
As soon as any signs of night blindness or dilated pupils are notices the dog should be taken to the veterinarian. The doctor may conduct the following tests:

  • Examine the eye‘s reflexes and capability to produce tears.
  • Blood test, blood pressure and chest x-rays might be performed to eliminate chances of any other health issues which cause blindness
  • May collect details about dog’s behavior in the night or near dark areas.
  • May perform Fundoscopy to examine the retina to determine if the there is any shrinking of the blood vessels, decreased pigmentation of the nontapetal fundus, increased reflection from the tapetum due to thinning of the retina
  • For many breeds there are specific genetic tests of blood or buccal mucosa for PRA
  • The electroretinogram can be useful in the early diagnosis of many forms of PRA.

What is the treatment for Progressive Retinal Atrophy?

  • There is no cure and no medical treatment for PRA; however oral nutritional antioxidant supplementation could be prescribed to support the retinal health of affected dogs. The goal of antioxidant supplementation is to help slow the deterioration of the retina to "buy some time" visually.
  • DNA blood testsavailable, to determine if dogs are likely affected with PRA, are likely carriers for PRA, or are not likely carrying the PRA gene. These tests are usually performed on purebred show dogs and breeding animals.
  • Dog with PRA who is already on oral antioxidant supplementation and still has some viable retinal function might undergo cataract surgery under limited circumstances. Following surgery, it is unknown for each patient how long vision will be present until all retinal tissue dies
  • If retinal function is completely lost in a dog with PRA but toxic cataracts are mild, antioxidant supplementation might be continued in these patients to help support lens health in an attempt to delay cataract progression.