Progressive retinal atrophy (PRA) is a common reason that dogs go blind. Since there is no treatment for PRA, any dog getting it will eventually go blind. According to "Dog Owner's Home Veterinary Handbook," PRA was first identified in a Gordon setter in 1911. It is now found in more than 85 breeds and can happen to mixed breeds. It is also called progressive retinal degeneration (PRD).
-
Significance
-
In any type of PRA/PRD, the photoreceptor cells in the retina become more degenerated. First the rods are affected, which means the dog can't see in dark places; then the cones are affected. PRA always happens in both eyes and not just in one, unless the dog only has one eye. Depending on the type of PRA, the dog will either go blind rapidly or gradually.
First Symptom
-
According to "ASPCA Complete Guide to Dogs," the first sign of any type of PRA is night blindness. This is when a dog will be reluctant or afraid of walking into any dark area, indoors or out. Turning on a light can often encourage a dog with night blindness to relax and act normally.
Types
-
Puppies can get early onset slow progression or retinal atrophy or early onset rapid progression retinal atrophy. In either case, the puppy will be completely blind by the time he is about two years old. Dogs six to 14 years old can get late onset PRA or sudden acquired retinal degeneration.
Diagnosis
-
Tests include an eye exam to check the eye's reflexes and capability to produce tears. According to Dr. Noelle McNabb, blood tests, blood pressure test and chest X-rays may have to be done to be sure the dog is suffering from PRA and not another ailment like tick-borne diseases or high blood pressure, which can cause sudden blindness.
Prevention
-
The cause of PRA is the autosomal recessive gene. It is always passed from parent dogs to their puppies. No dog with PRA should be bred. People on the lookout for a healthy puppy should check the Canine Eye Registration Foundation (CERF) to see if the parents of a potential puppy have CERF certificates. One can also contact the Institute for Genetic Disease Control in Animals to see if the parent dogs are registered.
-