PRA (Progressive Retinal Atrophy) is an inherited eye disease that can result in blindness at a young age. A breeder needs to use great care to breed away from PRA. In the past, we did this by having breeding stock examined by a Board Certified Veterinary Ophthalmologist for signs of PRA. This examination needed to be done yearly, and the results registered with the Canine Eye Registration Foundation, (Cerf). There were problems with the Cerf exam, a dog could get a normal test at a young age, but still develop PRA at a later age. Also, the Cerf exam could not tell if a dog was a carrier or not, so it was very difficult to know whether a breeder was producing pups that would develop PRA or not. Many times a breeder could be using a dog to produce pups for years before they discover that one or both of the parents were either carriers or affected. If two carriers are bred together, or an affected and a carrier, then some of the pups will be PRA affected and lose their sight. Recently OptiGen has developed a genetic marker test for PRA in the American Eskimo. This has been a great development for breeders to determine the status of their breeding stock, and aid them in breeding away from PRA.
Now that there is a genetic marker test available for the dogs, when purchasing a pup a buyer should always ask for a copy of the parent's OptiGen test results. If a dog is listed as OptiGen Normal/Clear, (formerly Pattern A), that means it is a non-carrier, it has NO PRA genes, and will not develop PRA or pass the gene to their pups. A carrier, (formerly Pattern B), has one PRA gene and one normal gene, will not develop PRA, but can pass a copy of the PRA gene to its pups. Affected, (formerly Pattern C), will most likely develop PRA and lose its sight one day, and will always pass one PRA gene to every one of its pups. A pup must have two copies of the PRA gene, one from each parent, to be affected.
Below is a chart to show what would be produced from a mating between the different genotypes:
Both parents Normal/Clear = NO pups will develop PRA
Normal/Clear to Carrier = NO pups will develop PRA
Normal/Clear to Affected = NO pups will develop PRA
Carrier to Carrier = 25% chance of developing PRA
Carrier to Affected = 50% chance of developing PRA
Affected to Affected = 100% chance of developing PRA
So it is very important to ask breeders for copies of OptiGen certification on the parents of your puppy for proof of their status, and if both parents are B's or C's, ask if the puppy is OptiGen tested, and request a copy of the OptiGen results on the puppy. There is no way a breeder can know the status of their breeding stock unless they do the OptiGen tests. Some breeders say the test is no good, but it does identify those dogs that are clear and those that are carriers with 99.5% certainty. So if a breeder is not testing their dogs, it is probably due to the expense of the test.
As always, if you have any
questions about any of my dogs or pups,
PLEASE PUT "PUPS" OR "AMERICAN ESKIMOS" IN THE SUBJECT LINE
DUE TO HIGH RATE OF SPAM, E-MAILS WITH NO SUBJECT WILL BE DELETED!
Carolyn E. Jester