FACT SHEET

Disorder: Progressive Retinal Atrophy (PRA)

Variety Of Poodle Affected: Toy, Miniature & Standard

Toys and Miniatures are more commonly affected with the prcd form (progressive retinal cone degeneration) and Standards are rarely affected by the prcd form.

Description : Progressive Retinal Atrophy (PRA--and specifically, the prcd form of PRA) is an inherited eye disease rooted deep in the gene pool of at least a couple dozen breeds. Gradual deterioration of the retina of the eye leads to blindness.

Symptoms: Dogs with prcd-PRA often become blind, and always have serious vision problems. First symptom may appear as night blindness and gradually progress to vision problems in the daytime and then to total blindness. In most breeds prcd-PRA manifests by the time a dog is at least six years old, after it has already been bred.

Mode of Inheritance: In order to develop PRA, a dog must inherit two copies of the defective prcd-PRA gene: one from its dam, one from its sire.

Method of Diagnosis: ERG or ophthalmoscopic methods by a veterinary ophthalmologist can be used for dogs already affected. For the prcd form of this disease, carriers and dogs which will eventually become affected as well as those free of the disease can now be identified by a DNA gene test available through

.

Age of Diagnosis: Varies and may occur late: i.e. 5-6+ years. For the DNA test, can be done as soon as it is safe for blood draws to be done. A genetic – DNA – test on blood can be performed on very young animals, usually as soon as your dog is big enough for your veterinarian to obtain 1-3 mls of blood (less than one teaspoonful).

Treatment: None. There's no cure, no treatment; no way to stop PRA. You can, however, prevent PRA in the next generation even though you can't treat it in the current generation. How? Through safe, selective breeding based on genetic testing.

Recommendations: Every dog used in a breeding program should have its eyes examined annually by a veterinary ophthalmologist or prior to being bred. The CERF exam tests for PRA and many other eye diseases known to Poodles. Progressive Retinal Cone Degeneration has a DNA test which is conclusive in diagnosis. As announced June 1, 2005, OptiGen now provides a direct mutation test for prcd-PRA. The Optigen prcd test is done on a small sample of blood from the dog. The test analyzes the specific DNA mutation causing prcd-PRA. The OptiGen test detects the mutant, abnormal gene copy and the normal gene copy. The result of the test is a genotype and allows separation of dogs into three groups: Normal/Clear (homozygous normal), Carrier (heterozygous) and Affected (homozygous mutant). This is a simple recessive and carriers and affecteds can be safely bred to clears although the resultant offspring must be tested before being bred.

The information contained above is based on published research current at the time of writing and is accurate to the best of VIP's knowledge