Optigen Testing (by Diana Stevens, Wylanbriar Labradors, edited by Sue White, MBA, BA(Hons))
The BVA/KC eye testing scheme has been around for around 25 years. It has been tweaked and fine tuned and moved about but the general idea has remained the same. A dog is examined by an expert for the eye conditions common to Labradors, and is clear (or 'unaffected' as it is often written) then one can mate in safety to another dog, also carrying a current clear eye certificate and know you are doing the best possible by the puppies produced for future good eye health.
However eyebrows were raised when two dogs with clear eye certificates were mated, a puppy from that was tested at 2, 3 or more years of age, and FAILED his own eye certificate for Optigen GPRA. How can that be? Well, the answer is simple and that is that both his parents although clear themselves were genetically CARRIERS of the the condition, when put, perfectly ethically together, were always going to produce a proportion of pups affected with the most nasty of all eye problems, Late Onset PRA or GPRA as it is better known.
This finding initiated work on a DNA test which would show not only if the parents were affected or unaffected with GPRA but ALSO, importantly, the result the paper BVA/KC eye test itself could never detect, if they were Carriers.
After many years of waiting we finally have a test, run by the company 'Optigen' in the United States, to exactly as above, give the GENETIC eye status of any dog before breeding from it.
Results will return as your dog being either: Clear, Carrier or Affected.
This test is not to rule any dog out of the gene pool, but to give a clearer idea of the playing field and to be able to make responsible breeding decisions.
The various breeding combinations using Optigen results are:
|Optigen Status of Parents||Outcome for Pups|
|Clear x Clear||= 100% Clear offspring|
|Clear x Carrier||= 50% Clear 50% Carrier offspring|
|Carrier x Carrier||= 25% Clear 25% Affected 50% Carrier Offspring|
|Clear x Affected||100% Carrier offspring|
So you can see that when Optigen tested, even an AFFECTED dog could be mated to a clear dog and never produce a single puppy who will be affected by GPRA.
You can Optigen test from a very young age, around 6/7 weeks of age, if you undertake a Carrier x Clear mating, and don't wish to keep a Carrier puppy, you can Optigen test the best two or three pups (at a reduced rate for this what is called 'litter testing') and keep only a clear puppy. The Carrier pups will never develop the problem, of that you can be CERTAIN, and so can be sold as pets comfortably.
Testing is by way of a blood test at your vets, and booking a test online at the Optigen website - www.optigen.com . Sending the blood from your vets to Optigen by way of airmail post and paying for the test by credit card when booking. It is not complicated and not daunting. It also costs around £100-£150 per dog to test and this is done only once in a dogs life. A small drop in the ocean for the 'value' of the results to that breeder and the gene pool as a whole.
You hear SO many reasons for not Optigen testing. The main reason really being that breeders are scared of what could be the result. Years and years of clear eye certificates or worse still simply an opinion that they have had 'no eye problems' can lull breeders into a false sense of security.
There has been around a 35% return on Optigen tests finding that dogs tested from the UK are in fact Carriers. This is a high percentage. I am entirely practical that the majority testing are those who consider there *might just* be a problem so therefore are being proved right. But many lines where people didn't for a second think there was any problem there are finding, in fact there are.
There are no clear LINES only individual clear dogs. And they are only proven as clear if they are Optigen tested. A dog can clear (like one of my own several years ago) 7, 8, even 9 eye certificates in his life and sire hundreds of puppies without anyone realising he is a Carrier. Then just one Carrier bitch mated with him can mean several young dogs from that litter devastating their families by going blind at a very young age.
"Where does health testing end?" Some breeders will counter.... "You need to breed for the WHOLE Labrador NOT just eyes". And I agree, but with such a simple and reasonably priced test available to give a 100% genetic certainty, not just a 'stab in the dark' result that really in the scheme of things hip and elbow scoring do in comparison, the puppies produced by us and the owners that buy them deserve it.