|what is PRA||To do||the future||The history||the genetics|
PRA comes from Sweden/Scandinavia
|the TRUTH:||Some rumors are saying PRA was "invented"
in Sweden. This is NOT true.
The gene-defect is not national, it is breed-specific!!
There have been diagnosed PRA in dogs bred in UK, USA, Norway, Holland, Iceland, Sweden and Denmark, but of course most PRA-cases are found in those countries, who thoroughly test their dogs.
In Denmark and Sweden the breeders can't get their puppies registered unless both parents have been tested clear of PRA within the last 12-month before mating. If a dog is diagnosed PRA, then it will be excluded from breeding as well as it's parents and offspring.
Back in '92 Pia Johansen, Gold Wings, started gathering
eye-test-results. Hoping to map the gene in order to prevent breeding dogs who were
carrying the gene.
The number of carriers are significant
|the TRUTH:||In Denmark/Sweden where testing is mandatory and all results
are due to public disclosure, we are used to pedigrees with a number of
carriers in them -
We have learned to live with the risk, and we are able to do an intilligent choise when choosing breed-mate - and that IS not done by counting the number of carriers in the background:
The risk of the litter becoming affected or carries can be calculated if you know the incidence of homozygotes (affected) dogs in the population, in Scandinavia as testing has been done for 10 years our stock are 100% tested by now.
On this background, and the numbers I have achieved by the CERF, the average PRA risk is 4% and the single carrier risk is 32%
Imagine a 5 generation pedigree - there are 62 individual dogs.
Assuming there are 7 dogs who are known to be carriers, 41 is not tested,
making 21 being cleared as affected. Noone is known to be affected
If the great-grand father turns out to be affected the risk will be
like this: 11% for PRA / 45% for single carrier. There are now 9 carriers
and one affected.
|Due to abuse and unauthorized copying, the eye-list will no longer be available to others than those serious breeders who send their eye-certificates to be included. We find it unacceptable, that people who clearly do not want to contribute in the completion of the list, otherwise like to benefit from people who do. At the same time we would like to stress, that older list's are no longer are valid - MANY dogs have changed diagnose - both from affected to cleared and vise versa - so please do not use older lists as reference for future discussions.|
the links below takes you to the breeders who co-operate in making this site and the PRA-list.
created and maintained by Pia Johansen
If you have any questions about PRA, please ask.
last update 05-12-05