I have a bitch cocker spaniel 14months old blue roan (molly)who was purchased from a rep breeder.molly has now developed cataract in both eyes(apparentlt heridit)before going ahead with surgery i now have to have a blood test to find out if molly has PRA the blood sample has to be sent to USA,altho mollys sire was eye tested I understand that the eye test in this country cannot detect if a dog is a carrier of PRA or is going to develope PRA in the future.as breeders supposedly eye test dogs each year,I do not understd why they do not have the blood test done,which would only have to be done once therefore workout cheaper and would give them allthe DNA info that would ever be needed regarding PRA,I now have to spend a nerve wrecking 4 wks waiting for blood results hoping molly will be free from PRA so she may have surgery,any other cocker owners shared this experience?

Never heard of having a Blood Test for PRA?? Can you please tell me more about it?. What does the vet call this Blood Test?
Thanks
Carolyne

have a look at www.optigen you will get lots of info from there

Hi Sean, I`ve looked at optigen many times & also corresponded with them. I still don`t have faith in the DNA test they do for Labradors, nor do I care very much for their ethics.
I find that post a bit strange really, I think most of the people who replied to you already know about optigen.
Christine, Spain.

chrstaine from spain will be able to help you out on this subject.

"any other cocker owners shared this experience?" No I haven't. Both my boys are tested clear for PRA on an eye scan. I can only assume they are doing a full DNA scan to see if PRA is in the genes - don't know for sure though. Jane S will be the one to advise on this one.

PRA is tested for annually by scanning the dogs eyes to see if they show any signs of PRA. Not all reputable breeders test all their dogs all of the time, it is voluntary. Some know their lines well enough to be confident it's not there. If however, anyone buying a puppy is not sure then they should look elswhere for a puppy where both parents have been tested. Cataracts is not PRA though so I'm not really sure what's going on here.

I think from what you are saying is that if there are signs of PRA in the DNA then the vet will not do surgery for the cataracts because she is going to have future problems with PRA as well. If that is the case then not sure I agree with that one. As long as you are not going to use Molly in a breeding programme - then even if she does carry PRA - she's not going to pass it on and he won;t know that she's going to actually develop PRA itself. The cataracts imho, should be treated as the current situation because at 14 months - Molly should have a long and happy life in front of her that should not br impeded by poor sight if it can be treated.

You say you got Molly from a reputable breeder - have you spoken to that breeder about the problem before going down this DNA route? If they are reputable like you say - then they will want to know of this problem for future information at least even if there is nothing they can do for Molly.

jmho

Pam n the boys

Hi Sean, like Pammy says, the blood test must be a DNA test. PRA does cause secondary cataracts & although a cataract, they are not heredetary. But your dog is young, so don`t know if you would see them now. I have used the DNA blood testing scheme & found it to be absolutly wrong in the results it gave for my Labrador & that firm are no longer testing the Labradors for PRA. Also the DNA blood testing cannot tell you if she is a carrier with absolute certainty. I also know that the blood test is not 100% accurate & that may be the reason why breeders don`t use it too much.You could have her tested by an Opthalmologist vet, there are clinics run in the UK regularly & I think there will be some at Crufts, this would give you a second opinion for Molly. In fact I don`t know why your vet hasn`t suggested it. If Molly does have PRA then she will eventually go blind, if she is a carrier then she will not go blind, but if ever mated to another carrier then any pups produced will have PRA. I should think if she has cataracts now, whether or not she has PRA, she can have them removed, thats what I`d be looking to do anyway, also I`d like a second opinion from a specialist Opthalmologist as well. HTH.
Christine, Spain.

Sorry, just editing this to say that is my experience in Labs, so it may be different in the Cockers.

Just to clarify if a PRA carrier is mated to another carrier the likelhood is that i in 4 of the offspring will have PRA (a 1/4 will be clear and half will be carriers). This is the risk we all run when we breed with eye tested stock, as we have no way of knowing if either the dog or bitch are carrriers unless affected offspring are produced.

We could spend several generations, and because we breed selectively and moderately from bitches and dogs, even if they are carriers we may never know, as their parntners may all be clear.

If a clear and carrier are mated together no affected offspring can result, but half the offspring would be carriers.

Obviously no-one would use an affected for breeding, but in breeds where the condition is of late onset, very occasionally a dogs affected status may be missed before breeding. If this animal is mated to a clear partner, then all the offspring will be carriers, if it's partner is a carrier then there will be affected and carrier offspring, no clears.

In recessive conditions there will always be the risk of affected stock from unknown carriers being mated together, but the incidence is reduced when al breeding stock is eye tested, as the affected are weeded out.

Just to add to B/less accurate tables, through doing annual testing a dog/bitch proven carrier that has been mated, can prove the stud/bitch it was mated to,clear & not a carrier, if the puppies produced have gone on to say 6yrs old & not shown any sign of PRA, by again, themselves being tested annualy & certified clear. If you see what I`m saying! :) :) Thats also useful to know when trying to find out the carriers.
Christine, Spain.

It's not so easy in Cockers, Christine. We have such a variable age of onset - from 2 years right up to 10 years plus ie dogs that have passed annual eye tests every year can be found to be afflicted very late on in life. This seems to be a peculiarity of PRA in Cockers as opposed to other breeds like Labs which seem to have a much more fixed "window" for developing the condition & makes life v difficult for us Cocker breeders, as you can imagine :-)

Hi JaneS, thanks for that :) I didn`t realise the difficulties you have in cockers. I sympathise with you, very difficult indeed. Bad enough with early onset let alone at the age of 10yrs.
What do you think of the DNA test & are you finding the amount of dogs affected with PRA, going down?
Christine, Spain.

In Elkhounds it seems that we have definately got two versions of the disease, and now possibly a third. We have Early retinal degeneration, and alsos rod dysplasia, but most recently the 3 cases diagnosed in our breed, after two of them had been bred from sadly, there appeards to be a thid kind, and the Opthalmologists couldn't agree on it. It appears to be very slow to progress, and one affected bitch still has useful sight years after one would expect her to be totally blind.

Sad thing is that one of the bitches that was bred from had all three of her shown offspring become Champions, but as they are at least carriers (no affected as yet, aqnd they are nearing veteran age) they cannot be bred from.

It is very didficult with recessive conditions as carriers identities often don't emerge until they are grandparents or more, and one cannot remove a whole generation, or several from the population in one fell swoop. One is left with descendants of known carriers that of course may be clear, or some may be carriers. All breeders can do is not to have known carriers appearing on both sides of pedigrees.

Hi ,I agree that the morals of optigen are snake like,but as this is the only test available at the moment and although there is errors is it not worth using them to try to find out carriers or not?

Hi pam.the dna test is to tell me if molly is affected or carrier,if she is carrier then i will be getting the surgery done and not cheap both eyes in total £1600,yes i hav spoken to the breeder,i was told at the time of purchase that all her dogs where eye tested but now having looked at the pedigree only the sire has been tested,bit naive of me i know put hinsight is great knowledge

ru the same pam of jasper and buddy if so enjoyed your site.linked to it thro loursima,altho molly did not come from lourisma,(blueacre)

Hi Sean - yes that's us:D. Glad you liked the site - I must get round to spending some time re-vamping it - it's in desperate need.

Good luck with Molly - it's certainly going to hurt the old bank balance.

Pam n the boys

As yet PRA DNA tests that identify the gene are only available for Irish Setters, and Pembroke Corgis.

In America a linkage test was developed (they didn't find the gene, but found genes that often occur close to the probable PRA gene, as I understand it) in a couple of other breeds. I think Labradors and maybe one of the cockers. Beleive there were five breeds.

As Christine has said it was proved to not be as accurate as had been hoped. Also it was a patented test, so it can only be done by the Lab that patented the test!

I think patenting medical knowledge such as discovering the gene and keeping it under wraps for a price is responsible gene totally immoral.

Until a spppecific gene test becomes available, th4en breeders will have to rely on annual eye testing, which will only show up affected. As the linkage test has ben shown to be unreliable, what faith can one but in false negatives or positives.

If only it were that simple :(

Optigen have a marker gene test available for Cockers in the USA but because it is a test based on marker genes rather than the defective gene for PRA, it is not viewed as being 100% reliable & many owners have disputed the results of this test in the US. Optigen have patented the test & will not allow the Animal Health Trust to use it in this country & consequently any UK Cocker breeder who wishes to have their dogs DNA tested must be prepared to send the blood to the US. This is extremely expensive especially if you have a number of dogs, as most breeders do. So it's not really surprising that the majority of Cocker breeders cannot afford to send blood to the US for a test which is not thought to be totally reliable anyway! So, really all we have available is eye-testing on an annual basis. As you rightly say, this will only weed out affected animals from the gene pool not carrier animals or those who might go on to develop PRA at a later date. PRA does not tend to be an early onset disease in Cockers so it would be rare for a Cocker to have developed PRA at 14 months (although not impossible) I would add that not all cataracts are hereditary - congenital cataracts (present at birth) can be caused by external factors such as viruses/infections etc & at present Cockers are not one of the breeds proven to have HC (Hereditary Cataract). I appreciate you are worried about Molly but I think it is unfair to criticise breeders generally - if both Molly's parents had current clear eye-certificates, that is the best you can expect in this country. Most UK breeders would love the option of a reliable, affordable DNA test for PRA but sadly, we don't have it yet.

Hi JaneS thanks for your info,optigen is the firm that we will be using on the recommendation of pip boydell at the animal medical centre manchester apparently optigen have come up with a new test for cockers in Jan 2003 which supposedly gives much accurate results,I had been told by our own vet that juvenile cataract is hereditary?? mollys present condition is that the retin can not be viewed at the moment cos of the cataract and therefore we cant tell whether this is just cataract or related to pra and the blood test seems the only answer,for from critising breeders I was wondering why eye test ever year at a cost when the eye test in this country apparently can only tell you if the retin is working put cant tell you whether it is working 20% or 100% this seems less accurate than the blood test.The new blood tests margins of errors seem alot less now,lets hope it proves ok

Yes I've read that Optigen have improved their PRA test for Cockers but even they state there is still a margin for error because this is still a marker gene test. I'm not familiar with Pip Boydell I'm afraid. Is he or she an opthalmologist? Having talked to a number of eye experts in this country (including one of those researching a DNA test at the Animal Health Trust), none seem to think the Optigen test is a viable option for UK breeders at this time - the cost is $260 dollars for the test alone, excluding vet fees for collecting samples plus cost of shipping etc. I can't speak for anybody else, but I couldn't afford this test at the moment for my dogs & like Christine, I'm not impressed with with the ethics of Optigen refusing to share their test with other countries! The annual eye test will tell an owner whether their dog is showing the early signs of PRA long before physical signs like loss of sight may be obvious, enabling them to be removed from the gene pool. This is why breeders (well, the responsible ones :-)) eye-test because it's the only thing we have at the moment. Annual eye-testing should catch PRA before cataracts form - cataract formation as a result of PRA is normally a very slow & gradual process, often taking years rather than months.

Juvenile cataract may or may not be hereditary - it's hereditary in some breeds but it's not proven to be so in Cockers yet. Cataracts can be caused by other things besides faulty genes as mentioned before.

Good luck with the test anyway & let's hope Molly can go ahead & have her surgery soon :-)

Thanks.i let you know how we go on