Progressive Retinal Atrophy (PRA) is a heterogeneous class of retinal disorders that share a broadly similar clinical disease phenotype. The prcd-PRA test is done on a small sample of blood from the dog. The test analyzes the specific DNA mutation causing the prcd-PRA. The 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).