Labrador Retriever Forum
Is the Optigen test for RD effective in determining whether to breed or not or is it totally unrelated?
My understanding is that geographical folds will not be CERF'd even if this RD/OSD test is accepted by CERF.
Geographic folds are the next level up that no matter what, shouldn't be bred to another clear or not.
If your dog has geographic folds you already have clinical proof of RD. I wouldn't breed that dog ... I've worked for so many years to steer away from RD.
If a puppy you produced has geographic folds I would highly suggest testing both parents before breeding again.
It tells you if the dog is or is going to be affected(can produce blind puppies), carrier(Can produce blind puppies if bred to another carrier or affected)or clear (will not produce blind puppies)
If the dog is clinicaly affected the DNA test should come back positive >>> afected.
If you have a carrier, you can breed to a non carrier nor affected dog/bitch, and then test puppies that will be bred.
http://www.optigen.com/opt9_test_prcd_pra.html
The test is to determine if the dog has simple benign FOLDS or carries the OSD (OculoSkeletal Dysplasia) dwarfism gene. I did not read anywhere that it covered GEOGRAPHIC RD. I suggest you email or call Optigen or Dr. Aguirre at UofP.
From Optigen site: http://www.optigen.com/opt9_rdosd.html
Suggestions for Implementation of the RD/OSD Test: If a Labrador retriever or Samoyed is identified with Focal or Multi-focal retinal dysplasia (retinal folds) during an eye examination by an ACVO diplomate, currently the dog is not eligible for certification within the CERF registry. In this case, the OptiGen DNA test will determine if the folds are caused by the mutation responsible for OSD. A NORMAL OSD result will indicate that the retinal folds are not caused by the OSD mutation and represent the frequent benign Focal/Multi-focal retinal folds found in these and other breeds. If the presence of Focal or Multi-focal retinal dysplasia (retinal folds) is not associated with the RD/OSD mutation, then the dog is considered free of a major inherited eye disease. Please note that these comments refer only to Focal/Multi-focal reitnal dysplasia (retinal folds). Geographic retinal dysplasia may represent a different, possibly inherited, disease. OptiGen is approaching ACVO, CERF and other organizations involved with genetic eye registries to develop a system by which a dog once diagnosed as clinically "affected" for retinal-dysplasia-folds can be 'recertified' if it tests clear for the RD/OSD mutation using the OptiGen DNA test.
There are apparently at least three conditions associated with retinal folds. The first is RD/OSD, and the Optigen test will identify carriers for that, which apparently have geographic folds and if homozygous may have skeletal abnormalities. The second are the so-called puppy folds, which are found in only a limited number and in the lower part of the retina. I have been studying this type of fold for about 10 years now and have not seen any pathology associated with them. Dogs with this type of fold have tested normal on the RD/OSD test, but I don't think CERF will certify them. Of course, the folds almost always disappear by the time the dog is of breeding age, and the dog could then pass CERF. So unless the puppies are examined at a young age, you would never know about the folds. I have taken a dog at 6 months to the same ACVO vet who examined him at 6 weeks, who has been cooperating with me on my study, with a copy of the 6 week eye exam showing the location of the folds, and she couldn't find them.
I just recently had some eye exams done (everyone passed just fine, but none of those dogs came from litters that had folds as puppies) and she told me about a condition she has seen in several breeds, including Labs, in which they have a U-shaped area of folds in the tapetal area. She says that these are designated geographic folds. She followed a litter of Goldens up past the age of 18 months, at which time the retinal dysplasia is supposed to occur, and they never developed any pathology at all. I also have been contacted by someone whose Lab was diagnosed with geographic folds and was clear by the RD/OSD test. This was before I talked to my vet, so I don't know if that was the same kind of folds my ACVO vet just told me about. So it is possible there are four kinds of folds, three considered to be geographic, and the ones that are restricted in location, the "puppy folds" that disappear. I am convinced that the latter are completely benign, but so far CERF refuses to certify. I, personally have not used a dog from a litter that had puppy folds in my regular breeding program in the past, but I would not discourage people from doing so if the dog is clear by the Optigen test. I don't have any personal experience with geographic folds, just what my vet told me.
BTW, in case you are wondering why I have discontinued my study, I did not get any females with folds in my most recent litters, and I had no one to continue the study with! And then the RD/OSD test came along and answered my question.
Ten years ago I had bought a puppy from a seemingly eye clear line. ( I knew several generations of that program, and pet pups, too.) Imagine my horror when Dr. Aguirre found a tiny fold at about 12 weeks of age, but no other irregularities. However, he suspected from where it was and its size and shape that it was a benign puppy fold, that--if I understood correctly--the eyeball was still growing and the retina not quite flat. He told me to keep her as a breeding candidate but to bring her back in 6 months or so, but not over a year later. I couldn't wait that long, and when she was 6 mos old, I brought her back. There were no signs of the fold in the 6 mo old pup, and she cleared on CERF, plus he looked over the paperwork and pronounced her fit, as CERF went, to keep in the breeding potential. She still sees fine, has produced only eye clear pups, and is a happy almost 11 year old.
In my mind, puppy fold are kind of like the other wrinkles on the outside in the skin that will disappear as the puppy matures. Very different from blinding and/or skeletal dysplasia, the latter which we saw in rescued field bred pups. I may do the RD test on her just for the heck of it.
I guess I still don't understand why, if a bitch is diagnosed with geographic retinal folds on a second exam, it was not seen on an 8 week exam, and she clears the RD test, why she couldn't be carefully bred to a clear dog. Are geographic folds dominate? By the way the parents are still clear and both are over 7. 
If anyone is planning on doing the RD/OSD test, next week is a good time to do it. The test is currently on sale for 10% off until the end of March and between March 11 - 17 Optigen is having discount days for an additional 25% off. It is a significant savings, since the normal price for the test is $160!
When Optigen talks about their test, they are clear in their statement
Geographic retinal dysplasia may represent a different, possibly inherited, disease.
So the Optigen test is not for this type of RD.
If your eye guy saw this on a 2nd exam and not the first, he probally made a mistake the first time, it was probally there but he missed it as puppys usually squirm plus the doctor is only human.
Dont breed to Geographic RD, it is hereditary and will be inherited.
OK, so Optigen says geographic folds "may" represent an inherited condition, but you know better and say "it is hereditary and will be inherited"?
Please share with us your medical, veterinary, and genetic training.
Does anyone know if dogs with geographic folds that do not have the RD/OSD mutation do in fact develop retinal dysplasia? The tendency to develop puppy folds is inherited, but so what, if there is no pathology associated with it? I am sure of this for the puppy folds, which are non-geographic, but as I said above, I have no experience with geographic folds.
I am willing to bet that she will test clear.
Thanks Forestwood for the heads up on the March 11-17 25% discount!
I'll be taking advantage as I have a gift certificate I won at a specialty raffle for 1-test half off, and that along with the discount will get me an Optigen prcd-PRA test for $62.35!!
I was told that the geographic folds will not progress, that what ever they are at birth is what they stay for the life of the dog. I'm guessing that a future generation could be worse and perhaps be born with retina dysplasia, but I can't get a definitive answer, just told don't breed her. Yet I'm told she's fine, and she'll never go blind, at least not from the folds.
To huh??????????
If you dont like opinions I suggest you not read forums. However, my suggestion is the same as Dr. Art Siegel's at VMDB/CERF. Feel free to contact Art and ask him his qualifications and schooling.
Peggy, here is what I am wondering about:
if the RD test actually covers all forms of retinal dysplasia, such that seeing folks is not really helpful any more, alongside the Optigen test, wouldn't that mean then that CERF is sort of much less important? Then if CERF accepts that reasoning, folks would slowly stop doing annual Cerfs no? What organization would put themselves out of business if they could help it?
Or is this not correct thinking?
Bonnie
From the CERF website. It does NOT seem to have been updated since the Optigen RD/OSD test came out.
Retinal Dysplasia and Retinal Folds
The retina is the neurological structure in the back of the eye which receives light and converts it into an electrical signal. This electrical signal is transmitted to the brain by way of the optic nerve and is interpreted by the brain as vision. The embryological development of the retina is quite complex. It forms from a small part of the front of the primitive neural tube, the structure that becomes the nervous system (brain and spinal cord) of the adult. Malformations of the retina before birth are rare but can be due to either hereditary or environmental (in the uterus) influences. Retinal dysplasia is a type of retinal malformation. The word "dysplasia" simply means "a defective development of an organ or structure". Retinal dysplasia occurs when the 2 primitive layers of the retina do not form together properly. Mild dysplasia manifests as folds in the inner retinal layer. These are called "retinal folds". In "geographic" retinal dysplasia there are larger areas of defective retinal development. In the severe form of dysplasia, the 2 retinal layers do not come together at all and retinal detachment occurs. Retinal dysplasia is not progressive. It is a congenital defect and animals are born with as severe a condition as they will ever get. Retinal dysplasia can be detected as early as 6-8 weeks on a CERF examination. However, because the size of the eye is small and young puppies are often wiggling during examination, a 6 month recheck is recommended in order for the ophthalmologist to better see the back of the eye.
The cause of retinal dysplasia in most breeds is genetic although prenatal infections with herpesvirus and parvovirus may also lead to it. Retinal dysplasia is reported in 25 of the 100 breeds of dogs listed in the 1996 edition of the CERF book Ocular Disorders Presumed to be Hereditary in Purebred Dogs. Twenty-four of these breeds had retinal folds reported, and 11 had geographic areas of dysplasia and/or retinal detachment. Simple autosomal recessive inheritance has been suspected in Akitas, American Cocker Spaniels, Australian Shepherds, Bedlington Terriers, Beagles, Dobermans, English Springer Spaniels, Labradors, Rottweilers, Old English Sheepdogs, Sealyham Terriers, and Yorkshire Terriers. The means of inheritance has not been determined in many breeds. In Labradors and Samoyeds a combination of retinal dysplasia and skeletal defects has been described. This condition is known as oculoskeletal dysplasia. In this condition an autosomal dominant gene is thought to be responsible for the genetic defects. Homozygous animals have skeletal changes and mild to severe retinal dysplasia while heterozygous animals usually have mild retinal dysplasia.
Retinal folds rarely cause vision problems for the individual dog. They represent small blind spots which are probably not even noticed by the dog. However, large areas of dysplasia (geographic dysplasia) may lead to large deficits in the visual field and dogs with retinal detachments are completely blind.
There have been many questions recently about the certifiability of dogs with retinal folds. Retinal folds may be seen in many breeds and still pass a CERF examination and receive a CERF number. This is due to the fact that the condition is thought either not to be hereditary in the particular breed or has never been shown to be connected to serious (blinding) forms of dysplasia. In some breeds, particularly Labrador Retrievers, Samoyeds, and English Springer Spaniels, individuals with retinal folds are NOT given a CERF number. Since retinal dysplasia is common in these breeds and dogs and bitches with retinal folds can have puppies with blindness and/or skeletal problems the gene should not be perpetuated. In all breeds, individuals with geographic and retinal detachment forms of retinal dysplasia are NOT certifiable.
The RD test doesn't cover anything but RD/OSD. I don't think that's in question. My question is how significant the other forms of RD really are. I'm convinced that puppy folds are not a health problem, having now followed a number of dogs with that condition to maturity and beyond. I would have statistical significance for that opinion if the condition were caused by a single fully penetrant gene, but I don't think it is.
I just had all my Optigen A dogs reexamined (I don't do CERF, just have them examined by my ACVO vet) because there is always the possibility of hereditary cataracts. I haven't had one in 25 years, but I will continue to do the tests. I am taking my puppies to be examined because I figure that if the entire litter and both parents are clear of folds, I won't do the Optigen test for RD/ODS. It's cheaper to have the litter examined than to have breeding prospects tested by Optigen. I will say that having the PRA Optigen results has taken the painful suspense out of yearly eye exams!
As for CERF's motivation, I don't know why they have refused to accept the puppy folds even before the Optigen test was available. They do certify folds in some other breeds. My vet says she can easily tell the difference and in ?? years of experience (she's at least in her 60s) has never seen them associated with any pathology. So I wasn't really holding my breath to get those Optigen results back. I, personally, don't think they have much grounds for withholding certification for the puppy folds.
That is an interesting statement that the condition is not progressive. Is that really the case? I thought detachment of the retina could occur in mature dogs. Am I misunderstanding what they are saying?
Okay, if CERF says this: In some breeds, particularly Labrador Retrievers, Samoyeds, and English Springer Spaniels, individuals with retinal folds are NOT given a CERF number. Since retinal dysplasia is common in these breeds and dogs and bitches with retinal folds can have puppies with blindness and/or skeletal problems the gene should not be perpetuated."
and
Optigen can test for RD which is a gene test, if you are clear, the gene tests says you are clear for RD. Is CERF claiming there are several
Or, is there one RD and there is now a gene test for it, and folds with a RD test of clear are irrelevant? But CERF doesn't want to actually acknowledge that since it is a money loser?
Or am I all wet?
Bonnie
Bonnie, that makes sense.
CERF has a business reason for refusing to acknowledge even the existence of the RD/OSD test or accept its results. As they lose "turf" to dna testing, they are becoming more protectionist -- another good reason for Breeders to use common sense in their decisions, not just blindly follow what they're told to do.
Oh boy....
you're speaking about yourself, then, Maureen?
At least up until now, the rationale appears to have been (and I must say that I have never talked to anyone at CERF) that one could not reliably tell the various types of folds apart in Labradors, so, since the RD/OSD condition had a serious pathology associated with it, they would not certify any Lab with folds because they could be confused with RD/OSD. That rationale doesn't hold water anymore, so they should begin to certify dogs that are RD/OSD clear unless they are saying that the seriousness of the other types of geographic folds is unknown.
I don't see CERF as in competition with Optigen here because there are other eye problems such as cataracts that occur in Labradors. And CERF has never given new information about the condition of a dog's eyes, anyway; they just pass judgement on what is breedable and what is not, using the report from the ACVO vet. If you trust your ACVO vet's opinion and keep up on what is generally accepted by breeders in your breed, CERF certification is really for the benefit of other people.
CERF is set up to provide a storage and processing service for ACVO exam information. This data is tabulated and made available to breed clubs, members of CERF, researchers, etc. Their basis for any information is the EXAM FORM. They issue registration certificates based on the guidelines provided for each breed.
The parent clubs (coordinating with the ACVO) decide which anomalies are allowed to certify as "breeder options" and which are "fail" criteria. For example, Persistent Pupilary Membrane is a breeder option in Labs, but a failure in Basinji. This is not at CERF's discretion - they issue certificates or not based on the input from ACVO and the parent clubs.
Because RD has been associated with skeletal deformation, it was ruled a "fail" observation. Again, CERF did not make this decision unilaterally - it was told how to handle the situation by the governing bodies. Now that there is a DNA test for the OSD form of RD, it is up to the ACVO and LRC, Inc. to decide how the issue should be handled. They can instruct CERF to issue certifications with a "breeder option" note about RD if a copy of the DNA clearance is attached to the exam form. They can opt to keep it as it is. It is up to the two governing organizations to decide how it will be handled in the future.
It is not about money, "turf" war, or any other egotistical, petty issue that egotistical, petty people might wish to blame. It is a matter of the chartered function of CERF and an obligation to serve the interests of the various organizations that govern certification issues.
Thanks, Maureen. I did not realize that there are two organizations, ACVO and CERF. Can you clarify- I assume that the ACVO is composed of experts- ACVO certified vets? And CERF is therefore only the organization that collects the data and issues certificates? I did know that breed organizations had input and had forgotten it. I do not get CERF certificates, myself, although I would send in one if there was a question of whether or not the dog would qualify.
So it sounds as if it is the LRC that has not acted on the new information.
