As it is with humans, a dog’s eyes are his window to the world. A decrease in or loss of vision altogether is debilitating and can greatly diminish a dog’s quality of life. A common genetic reason for blindness in dogs is a condition called Progressive retinal atrophy (PRA), also known as progressive rod and cone degeneration (PRCD).
What is PRA-prcd in Dogs?
PRA-prcd is a group of degenerative eye disorders causing blindness in both eyes over time. As its name implies, this blindness is caused by the gradual deterioration and loss of function in the retina and its photoreceptors: rods and cones. The membranous retina lines the back of the eyes and absorbs, reflects, and perceives light. A dog affected by PRA-prcd therefore loses his ability to see clearly as the membrane deteriorates.
Which Dog Breeds are Affected by PRA-prcd?
Any dog, and even mutts, can be affected by various forms of PRA-prcd, however, it does affect some breeds more often than others. Here are just a few:
- Labrador Retriever
- Golden Retriever
- Cocker Spaniel
- Yorkshire Terrier
- Miniature Schnauzer
- German Shepherd
What are the Symptoms of PRA-prcd?
Any variation of the following are common signs that your dog may be suffering PRA-prcd:
- Cloudy eye surface or discoloration on the surface of the eye
- Greenish tinge to the surface of the eye under certain light conditions
- Bumping into furniture
- Tripping over objects
- Reluctance to go out in the dark
- Reluctance to explore
- Reluctance to navigate stairs
Can PRA-prcd be Prevented?
If your dog already carries the combination of genes for exhibiting symptoms of PRA-prcd, there is no way to prevent the inevitable through diet or lifestyle changes. However, there are promising advances in gene therapy that can help if they are accessible to you.
The best way to mitigate, if not eradicate, PRA-prcd in all dogs forever is for breeders to order DNA testing for PRA-prcd from a reputable laboratory and then use that information to breed responsibly. Make sure the PRA-prcd test for your particular breed is validated by the laboratory you choose.
There are 3 possible genotypes reported for Progressive Retinal Atrophy, Progressive Rod-Cone Degeneration:
- CLEAR: those having 2 copies of the normal allele and appear to be normal
- CARRIER: those having 1 copy of the normal allele and 1 copy of the PRA-prcd mutation but appear to be normal
- AT RISK: those having 2 copies of the PRA-prcd mutation and will develop blindness over time
What is the Treatment for PRA-prcd?
Unfortunately, the effects of PRA-prcd are irreversible, the disease cannot be cured, and it always results in complete blindness for an affected dog. However, you can make your dog more comfortable by keeping furniture in its current familiar location and being sure to keep the floor clear of obstacles such as toys. Be sure to also take your dog on a well-known route during walks to help prevent anxiety.
The Tip of the Tail
It’s important to remember that PRA-prcd is not a death sentence. Since vision loss is gradual, most dogs learn to adapt and go on to live happy, fulfilling lives.
In the late 1970’s my Briard was found to have CPRA. I took advice and my dog being female was not bred from. She lived a happy life until the age of 8 when she became ill with Cancer and as it was on the Vets’ advice she was euthanased. Chloe was from Avery famous Bloodline . All breeding had to Seaver’s. Dr Bedford here in the UK was very much a part of eradicating the eye deficiency in Briard. Chloe could spit a bird on the beach a long way off but would bump into trees in the woods.
What is the difference between crd4 and prcd PRA.
Hi, Catherine. They are different types of PRA, and therefore they have different markers and tests. The marker we test for is PRCD c.5G>A for PRA-prcd.
Hi my Dashound tested for PRD clear but with the breeders test she came up as a carrier. What’s going on
Hi, Marielys. Please contact us directly at [email protected] or call 800.625.0874
My English Springer 3 yrs 9 mos just diagnosed with PRA. She is the daughter of brother/sister parents and was sold to me. I contacted the breeder via email, they did not respond. Would her liter mates develop this as well and what abt the mother and father having bred with other non siblings; will they pass this along to them? The breeder is in another state and my puppy was seen by a vet before shipped to me. Should I call that Vet and let them know the situation too?
Yes to all your questions, Catherine. What a shame and good luck!
Hi my Lab mix of three years has tested positive for this. I have also had it diagnosed by a vet that specializes in eyesight. I was wondering if there is anyone I can contact about getting the gene therapy for him. His vision is beginning to degrade but is still decent. I would really like to stop this from progressing if possible. Any help would be much appreciated. Thanks
Hi, Daniel. We’re so sorry about your dog’s condition. We do not provide nor can we recommend specific facilities that may offer gene therapy for canines.