DNA testing for DM now available and a MUST for breeders

DNA testing for Denerative Myelopathy is here! Corgis are the only small breed that can get it. My dog, Yogi, has the symptoms, loss of rear leg use, and thanks to CorgiAid, now has a cart. Yogi had MRIs which showed his leg use was not due to spinal injuries. I just sent out the swab test and awaiting results.

It is the responsibility of breeders to wean this out of the breed. If you plan on purchasing a puppy, please know that breeders will not know if the parents have the gene as the test just came out. It is the duty of breeders to test all their dogs, both male and female parent to test for it. The test needs to come back, "clear." The parents need to be neutered/spayed if the test comes back positive ("affected"). We need to insist that breeders be responsible now so that we, the owners and our loving corgis don't go through this in the future. It is heartbreaking. Below are the websites for testing both using blood and swab.

You can order the test at this website:
https://secure.offa.org/cart.html.

Pembrokes with a probable DM diagnosis or 10 and older can get a
free test. The website with that info is:
http://www.caninegeneticdiseases.net/DM/resrchDM.htm.
The free test is more involved -- requires blood sample drawn by vet instead of
swab (cheek?) which can be done at home and the blood must be sent
overnight in an insulated container with cool packs.

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Thank you for posting this valuable information.
I responded to this thread then erased my response because I see it was bumped.

The profile page for Virginia says that Yogi passed away in June of 2009 from lymphoma. :-(

Sam, can we pull this off the front page? It may be very sad for the owner to see the reminder.....

Virginia, if you are reading this, I am sorry for your loss.
No, please leave on! I need to get the word out for Yogi's sake and future bred corgis! I miss Yogi, but this it too important!
Good information however I did wish to share some info a bit more in depth. Dogs may test clear,carrier or affected. It is possible that affected dogs may never show symptoms of the disease. In any case they should not be bred. Clear to carrier is an acceptable breeding choice as the gene needs both copies (one from the male and one from the female) to produce affected pups. I will tell you that the conversation of genetics gets far too deep for me so I can make no further explanation. Obviously it is only the breeders that can choose to test and choose to breed dogs that will not contract DM. The potential purchaser will do well to keep this information in mind along with other typical health testings that reputable breeders should perform. At this time you will probably find only few that are testing.
Those of us that have shared our life with a DM dog know the heartbreak of watching your beloved pal slowly lose the use of his body. We can give supportive care, obtain a cart, get great information by joining WheelCorgis and spread the word. This is becoming a fairly common issue within the corgi breed. Because the symptoms appear so late in life many similar breedings may take place before the breeder even knows. Testing gives them the informaton they need to make a better choice in making breeding selections.
Best of luck to you and Yogi. I cant recommend the WheelCorgis list enough. They were with me and most supportive the entire time I had with my dear Deion.
Sam, you and Virginia are both partially correct.
There is a high incidence of "at risks" in the breed right now, not so many carriers, a few clears.
"At risk" means they have two copies of the gene and can get the disease, and can pass on one gene for it.
"Carrier" means one copy of the gene and the ability to pass it on.
Clear means the dog has no genes for DM and cannot pass any defective genes on.
So here is how it works:
Breed a clear dog to a clear dog, results in only clears. No one gets DM.
Breed Clear to carrier, 50% clears, 50 % carriers. No one gets DM.
Breed Carrier to carrier, 25% at risks, 50% carriers, 25% clears. You are still producing at risks but carriers and clears don't ge the disease. A bit risky of a breeding but sometimes it's all you can do and test the pups, sell them with full disclosure.
Breed Carrier to At risk, 25% carriers, 75% at risks. This is less desireable and should only be undertaken by a breeder who knows the risks and is able to keep pups that cannot be sold at at risk. Or they can be sold with full disclosure.
At risk to at risk, 100% at risks.
At risk to clear, 100% carriers, no risk of the dog getting DM.
Bear in mind that these are statistical results and what the average would bear. I have a little of clears and carriers but probably won't be 50/50 clears/carriers (but could be). It's the average over a lot of dogs over time.
This all being said, you can breed an at risk dog but the best bet is to make it to a clear. That way you don't lose what you have achieved by years of breeding specific characteristics and can "upgrade" to a carrier to show/breed/love and ensure that no one gets DM. The other breedings using carriers and at risks are much riskier. Bear in mind that I have the lovely option of having 2 clear boys so I don't have to ever worry about producing a DM dog again, I hope!
I'm neither a breeder nor an expert, but I do work in a genetics lab and if I read that paper right, it's just a bit more complicated.
If either parent is "clear" (homozygous GG), probability of pups being carriers (heterozygous AG) is 25-50%, but none of those will be "at-risk" (homozygous AA).
In medical genetics, the term "affected" means that disease symptoms are present. If I got it right, most PWC are AA "at risk" but of those, only a few develop DM and become "affected".

The high incidence of the A allele in PWC makes me wonder if it's been inadvertently selected by breeders. Conceivably, it's tightly linked (physically close to on the chromosome) to some valued corgi trait, which will now be selected against unless/until they find a crossover separating the two. Stay tuned.
Yes, I did mention previously that the geneticists involved are NOT saying breeders should aggressively breed out the "at risk" dogs because of the low occurrence rate, and the fear that it would ruin the breed. If you click on the study link, it does say it could be catastrophic to the breed to only breed "at risks" to clears at this time.

I had come across another geneticists advising Chessie breeders to only breed "at risks" to "clears" IF they had DM in their line. If they had no history of DM in their line, they should not make such a drastic move, as it would cause a too-rapid narrowing of the gene pool. Since geneticists are looking for other genes that affect expression or suppression of symptoms, the idea is that if DM is in the line, those other mystery genes are likely present as well. The problem, of course, is that since age-of-onset is so late, breeders may not know the status of their lines until many dozens of puppies have already been produced. Please note that Chessies seem, early on, to have many more "clears" than the PWC.

One need only look at the poor Cavalier King Charles Spaniel to see the disaster that can result from an overly small gene pool.

DM is not a simple carrier/clear issue like, say, VwD.
Beth, how would we know if there was a history of DM? I've only ever had one dog that we knew about, that was from a different line that I had stopped working with. As has been mentioned many times before, DM would have been mistaken for disc problems, etc. Please define the "history of DM" since in 25 years of breeding, "I have never seen it" other than this one time. Do I believe that? Heck no! Either people thought their old dog could not walk anymore and had it put down, etc, etc. Now that we have a test and know what to look for and that it is there, yes, it is there.
From what the U of MO says, it is a simple recessive but apparently with a modifier gene or maybe even an incomplete penetrance. We don't have all the answers. It's simply amazing to me that people are in denial about the devastating effects of this disease JUST AS they were about hip dysplasia, eye problems, PDA, etc. Every single one of those diseases, and I mean every single one, has been fought over by breeders. "It's not a problem" "why are you looking for something that isn't there", etc, etc, etc. All of these have been found to be problems in the breed, now the gold standard is to at least do hips and eyes.

Once again, you say:
Yes, I did mention previously that the geneticists involved are NOT saying breeders should aggressively breed out the "at risk" dogs because of the low occurrence rate, and the fear that it would ruin the breed. If you click on the study link, it does say it could be catastrophic to the breed to only breed "at risks" to clears at this time.

And where exactly are you getting that anyone anywhere is saying to only breed at risks to clear? You keep saying this. But I haven't said it and neither has any other breeder who tests. I have an article in the upcoming Corgi Annual and I never said it there. I believe it is right to always "upgrade". I don't think breeding at risk to at risk or at risk to carrier will do anyone any good. You may indeed be doubling up on the modifiers that cause the disease to be expressed that way.

My PERSONAL belief is that I will not ever produce an at risk dog again. I feel that this is the right thing to do. I don't tell others what to do. My previous post was only to clear up that at risks could still be a great part of a breeding program. I personally also feel that if I pick up small ears along with clear for DM, that is a small price to pay.

And we have LOTS more corgis in the gene pool, and always will,more than KCKSs. They are all dying of heart problems anyhow. It's not a viable breed. Corgis will be the same way if we don't get people testing for cardiac problems, too.

Just my opinion. I'm not looking for an argument. But I feel until you are a breeder and have experienced this, it's really hard to say what is right and what is wrong.

John writes:
If I got it right, most PWC are AA "at risk" but of those, only a few develop DM and become "affected".

The high incidence of the A allele in PWC makes me wonder if it's been inadvertently selected by breeders. Conceivably, it's tightly linked (physically close to on the chromosome) to some valued corgi trait, which will now be selected against unless/until they find a crossover separating the two.

The first statement, maybe. That's what we know at this time. A lot of corgis never make it past 12 or 13. Maybe it doesn't express until 15 or 17 in some lines. There are a lot of ifs. But I will never have to worry about that if I make sure I don't produce them, now, will I?

Yes, the A gene could be linked to something else. But isn't most everything linked to something else? And that's what makes a breed of dog, that dog, or that horse or whatever animal you are speaking of.

I will never again produce an at risk dog. Period. I find it amazing that people seem to feel that this is wrong somehow? Can anyone please explain that? I'm not trying to be self righteous or self aggrandizing. I'm trying to make sure that families who take my pups never have to deal with that particular heartbreak again.
Just to clarify one point:

"And where exactly are you getting that anyone anywhere is saying to only breed at risks to clear? You keep saying this. But I haven't said it and neither has any other breeder who tests."

Well, to be honest, when you say that you will never personally produce an "at risk" dog again, then yes you are saying that you will only breed an "at risk" to a clear; otherwise you can't guarantee no "at risk" dogs. You then go on to say that breeding an at risk to a carrier or at risk will do no one any good, but again that is advocating breeding at risks (who seem to make up more than 50% of the gene pool) to clears (that only make up about 6% of the gene pool). I consider that a huge narrowing of the gene pool.

Also, I never said it was not a problem.

You say we have lots more Corgis in the gene pool, and from what I have read that is what I believe too. However, if the clears are as few in number as early tests indicate, and people are only going to breed at risks to clears, then yes we will inevitably have a sharp decrease in the gene pool.

I respect your vast knowledge, and you certainly have every right to breed for any set of traits you feel is most important. At least two people in the thread mentioned that at risks or carriers should only be bred to clears, and they are entitled to that opinion of course, and who knows what time will prove to be the best course? I was simply responding with another point of view, that of the geneticists who are not advising such an aggressive course of action at this time.
Just to clarify...When I am breeding clears to carriers or at risks, that is for that first generation or second generation only. If I produce a clear bitch (and I hope there are several in the current litter), then I can take THAT girl out to any boy I choose. There would be a slight bottleneck effect during the first generation or two, but once clears are being regularly produced, you can go back out into the regular gene pool to play again. My goal for the next two generations is to produce clears for myself and for other breeders who are like minded. When you are able to go out again, any genes are available.

Saying that I will never produce, myself, another at risk is not the same thing as saying that someone else should make that same decision. I feel so much for the people who are going through this awful disease, I want to see it gone forever.

I guess I don't see this as any different than making sure I breed to a dog with good hips, clear eyes and cardiac clear. I don't want to produce those things. Not only do I look for dogs who are clear with these tests (and cardiac clears are nearly impossible to find but I do the best I can do with it), but for siblings who are clear and at least grandparents. This makes for a huge amount of questions to a stud dog owner. (Or bitch if they want to use my lines.)

I guess I am reminded of the Portugese Water dog situation of the 1970s/1980s. We've been through this before. PWDs had some incredibly awful stats for poor hips. I can't remember exactly but am thinking it was in the 70% range, I know it was over 50%. Same arguments ensued (although I hope that I'm not being seen as argumentative here). The breeders made hard choices, In 20 or 30 years, they had the HD problem down to a liveable level. And that was a very small gene pool to start with as there weren't that many over here. I have also watched Basenjis go through the same thing with Falconi syndrome and the Bedlingtons with copper toxosis. They thought Bedlingtons would become extinct because the problem was so widespread. Getting a DNA test actually helped because the only other way to find if a dog had it was a liver biopsy, expensive and there is always a danger with anesthesia. These are breeds with very small gene pools, yet they have survived. So I have hope that with so many more corgis that we will be just fine.

Joanna, you are right, DM will not keep dogs offf the operating table for IVDD. They are two separate diseases....I used to believe what you do about more IVDD dogs being out there than DM dogs but it's been pretty incredible, now that we have the test we are finding that there are lots more DM dogs than dogs who have gone thru an accident or something to injure their spines.

My message is still to test. We need to see what the true numbers are. We need to make careful breeding choices taking all areas into consideration. And it is a personal choice of mine to make sure that any dogs I produce do not lie in your front room, flopping about like a fish and breaking it's owners heart as they slowly watch it die. I hate to be graphic but gosh, who would want this for their best friend? I have long decided that many breeders don't care about their dogs once they leave their home. I was doing OFAs when no one else was. And eyes. I was one of the first to get busy with vWD.
Thank you so much, Millie! WE NEED TO TEST so that people like me and dogs like my Yogi can avoid suffering! We need to continue to get the word out! He was only 9 when he developed DM and I lost him a year later. No more! Keep getting the word out!
One question: in humans, this gene mutation causes ALS and is very prone to spontaneous mutation-- those who have the mutation frequently have parents with normal genes. Any idea if this is true in dogs?

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