The Entlebucher and PRA
(Progressive Retinal Atrophy)
INHERITED OCULAR DISEASES IN THE EMD
HELPFUL TIPS FOR LIVING WITH YOUR PRA DOG
The Entlebucher, like several purebred dogs as well as canines of mixed heritage, can be afflicted with Progressive Retinal Atrophy (PRA). PRA is a hereditary disease of the eye that causes blindness.
PRA is a blanket term for many types of retinal diseases, all of which result in blindness. There are two groupings of PRA — early onset, and late onset. In early onset, PRA poor vision in low light may be detectable shortly after birth, with total blindness occurring from 1 to 5 years. In late onset forms, night blindness occurs from 1 to 5 years, progressing to total blindness anytime after 3 years of age. Most Entlebuchers have the late onset variety with very few afflicted with early onset PRA.
Because of the late onset of PRA in the Entlebucher, the best efforts of breeders and Breed Clubs worldwide could not totally eliminate the chance of puppies being born afflicted with PRA. Due to the very nature of late onset PRA, 100% accuracy was impossible. Healthy carriers of PRA (dogs with only one gene) would never show clinical signs themselves; but when these healthy carriers were bred to other healthy carriers or afflicted dogs(dogs with two genes), they could produce pups that would develop PRA. These offspring would eventually go blind, but not until the parent had been bred several times, or sometimes even retired, showing that despite the most diligent efforts of breeders and Breed Clubs, the disease was simply impossible to control without DNA testing.
But Entlebuchers are one of the lucky breeds. We now have a breed specific DNA test!
Thanks to the devotion of our Entlebucher breeders and the individual owners worldwide who came together to supply the needed blood for the PRA Research Program, the dedicated doctors were able to find the genetic test for PRA. We can now identify the 3 patterns in our Entlebuchers by sending blood to OptiGen for testing. PRA will not be an issue anymore on those dogs that have been tested and typed.
Pattern A: Clear and clean dog — does not carry any PRA genes
Pattern B: Healthy Carrier — carries one gene but will never get PRA
Pattern C: Afflicted dog — carries two PRA genes and will ultimately go blind
Breeders can now test their breeding Entlebuchers to find out whether they are Pattern A, B or C and can choose accordingly which dog to breed to their own PRA Patterned Entlebucher.
The genes for PRA are recessive and an afflicted (Pattern C) dog has received a gene from each parent. As long as one of the parents is Pattern A that is all that is needed to insure that none of the resulting offspring will be Pattern C. So all breeding Entlebuchers can continue to breed, only now breeders will know which dogs they can breed to and which dogs they cannot. PRA can be so easily controlled without taking any breeding dogs out of the gene pool.
But in the meantime, there are some wonderful beloved Entlebuchers already out there that are Pattern C. We have formed an e-group for owners of Pattern C Entlebuchers, so you can chat with other owners, get support, share stories at the PRA SUPPORT GROUP.
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