Health & Testing
prcd-PRA: The Most Important Eye Test in Small Dog Breeding
prcd-PRA is a preventable cause of blindness in dogs — and it affects multiple breeds we work with. Here's how it works, who needs testing, and what clear/carrier/affected means.
March 3, 2024 · 5 min read
What Is prcd-PRA?
Progressive Rod-Cone Degeneration (prcd-PRA) is an inherited disease causing gradual death of the rod and cone photoreceptor cells in the retina. Rods die first (causing night blindness), followed by cones (causing progressive loss of daytime vision). Affected dogs typically begin showing signs in early to mid-adulthood, progressing to total blindness. It is caused by a recessive mutation in the PRCD gene.
Which Breeds Are Affected
prcd-PRA affects many breeds, including: all Poodle varieties (Toy, Miniature, Standard), Cocker Spaniels, Labrador Retrievers, and several others. Cavalier King Charles Spaniels carry a different PRA variant (PRA1 and PRA2). Yorkies are at risk for a different form as well. Any Poodle or Cavalier cross (Cavapoo, Cockapoo, Goldendoodle) inherits risk from both parent lines.
The Three Test Results and What They Mean for Breeding
- Clear (N/N): No copies of the prcd-PRA mutation. Dog will never develop prcd-PRA and cannot pass the mutation to offspring.
- Carrier (N/PRA): One copy. Dog is healthy and will never develop the disease. But can pass to 50% of offspring. Carrier × Clear is safe — no affected puppies possible.
- Affected (PRA/PRA): Two copies. Dog WILL develop progressive blindness. Should not be bred.
Why This Test Is Non-Negotiable
PRA is 100% preventable through simple DNA testing and responsible pairing. Any breeding dog not tested for PRA — in an affected breed — is an irresponsible pairing regardless of any other quality the dog may have. At Star Struck Puppies, our breeding dogs are DNA health tested, and we verify clear or carrier + clear pairings for all PRA variants relevant to our breeds before any breeding takes place.