Progressive retinal atrophy (PRA) is a common cause of blindness in purebred dogs. It is an inherited disease and there are several different forms resulting from defects in different genes. Most forms are due to a defect in a single gene and are inherited in an autosomal recessive manner. We have been investigating genes that could cause this disease and seeing if they are the cause of PRA in several breeds of dog. In one breed we have evidence that the PRA is caused by a defect at a genetic locus already known to be responsible for PRA in several other breeds. We have shown that this locus is not involved in PRA in the other breeds. We wish to investigate a further 50 genes to see if they are involved in PRA in any breeds. If we identify the gene defect that causes the disease in one or more breeds we will develop a DNA test for the defective gene. Such a test will allow breeders to eradicate PRA from their breed.