Pap-PRA1 Testing for Progressive Retinal Atrophy in Papillon Dogs

Pap-PRA1, a unique form of progressive retinal atrophy (PRA), affects the Papillon dog breed and its Phalène variant. This inherited condition causes gradual loss of vision leading to irreversible blindness, significantly impacting a dog's quality of life.

Progressive retinal atrophy is a common hereditary eye disease among many pedigree breeds, but the gene mutation involved varies between breeds. The Pap-PRA1 mutation specifically affects the photoreceptor cells in the retina, responsible for transmitting light and colour signals to the brain. While dogs with PRA are typically born with normal vision, symptoms often appear between four to six years of age, starting with difficulties seeing in low light.

Understanding Pap-PRA1 Progressive Retinal Atrophy

The Pap-PRA1 mutation involves a genetic fault in the CNGB1 gene and follows an autosomal recessive inheritance pattern. This means a dog must inherit two copies of the mutated gene—one from each parent—to be affected. Carriers who inherit only one copy do not show symptoms but can pass the mutation to their offspring.

It is important to note that the known Pap-PRA1 mutation accounts for about 70% of affected dogs, indicating at least one other unknown mutation may also contribute. Testing helps detect affected dogs and carriers, aiding responsible breeders in managing this genetic health risk.

Which Dogs Are Affected?

The Pap-PRA1 mutation is exclusive to the Papillon breed and the Phalène, a variety distinguished mainly by its drop ears rather than erect ears seen in the Papillon. "Papillon" and "Phalène" translate from French as "butterfly" and "moth," inspired by the dogs’ distinctive fluffy ear hair resembling wings.

Crossbred dogs with Papillon lineage may carry the mutation without being affected but can still pass the gene to their puppies, especially if bred back to a purebred Papillon.

Inheritance Patterns Explained

Because Pap-PRA1 is autosomal recessive, the combination of parental statuses determines the puppy outcomes. Dogs are categorised as clear, carrier, or affected following genetic testing. The breeding pair’s statuses have predictable probabilities for the next litter:

• Two clear parents produce only clear puppies.
• Two affected parents produce affected puppies only.
• Two carriers produce 25% affected, 50% carriers, and 25% clear puppies.
• A clear and a carrier produce 50% clear and 50% carriers.
• A clear and an affected parent produce 100% carriers.
• A carrier and an affected parent produce 50% affected and 50% carriers.

How to Get Your Papillon or Phalène Tested

Testing forms part of The Kennel Club's official DNA testing scheme for Papillons, supporting breeding decisions to reduce PRA incidence and improve breed health. Responsible breeders use test results to avoid mating pairs that could produce affected puppies.

To arrange testing, your vet will collect a DNA sample via a buccal swab or blood sample. This sample is sent to a Kennel Club approved laboratory, which processes the test—typically returning results in 3 to 5 working days. The outcome will indicate your dog’s status as clear, carrier or affected and will also be recorded by The Kennel Club.

Early genetic testing allows breeders and owners to make informed decisions with the goal to gradually eliminate this mutation from the breed's gene pool, protecting future generations from progressive blindness.

For those interested in responsible breeding or adopting Papillon puppies, it is essential to enquire about Pap-PRA1 testing and results. Prioritising health testing demonstrates dedication to the welfare and longevity of these delightful dogs.

Find reputable Papillon puppies and Papillon breeders that support health testing protocols and ethical breeding practices.