DM Degenative Myleopathy

Degenerative Myleopathy is a cruel condition which in later life affects the rear of the spine. On the picture above, an unfortunate Pembroke can be seen trying to enjoy a dip whilst in a stream.

About Degenerative Myleopathy

DM can be seen

The easiest way is to show DM is though articles Universities and people who have seen this disease

One of our Owners

We were recently asked if we could send a pup to Japan because they knew we test our corgis for DM and they had been watching use for some time. We had a DM, vWD clear Tri boy from our Cruft best puppy in breed 2015 girl. The owners have on there site the links to Gifu Univerisity and its Animal Medical Centre which does research. The website contains video’s showing Pembrokes in harnesses which can be distrurbing to those who don’t know the diseases and bad memouries to those who have seen it in their corgis. Here is the link

Which can be found here along with other

Since first described in 1973 by Damon Averill, DVM, DM has stood for a degeneration of the spinal cord due to an unknown cause. In 2009, a mutation in the gene superoxide dismutase 1 (SOD1) was described to underlie the cause of DM. The University of Missouri was the first to have a test for DM and their website link is

Advise on massage


Instead of explaining the disease myself I have copied in a very informative statement from an owner in the US and I cannot fault it. But I will add – here we think DM is genetically attached to the Fluffy / Glamour coated corgi and brought on by line breeding. You can get gene migration, I have seen it first hand and can describe but that’s another page. Contact us for more details.


A common question in the corgi world today is, do you DM test? It is the new craze and one of the reasons puppy prices have suddenly shot up. The problem? It’s not fully understood or accurate and this new fad is causing many breeders to test for DM without regard to any other genetic issues that could be going on! This is very concerning.

Nessa Gier, a show breeder, explains it beautifully! Here’s what she has to say on DM:

​”​DM- Ok, well I’m going to say I’m sorry in advance on writing a book here on information on DM. It’s a VERY hot topic with a lot of breeders in the US (still being totally ignored by show breeders in Europe at this time) But A LOT Of the info out there is seriously flawed and there are A LOT of misinformed people. Ok – First off. What is DM? Degenerative myelopathy (DM) is a progressive disease of the spinal cord in older dogs. The disease has an insidious onset typically between 8 and 14 years of age. Pembroke Welsh corgis are one breed that is at higher risk for DM due to their longer spinal cords and a genetic predisposition in the breed for the condition. What causes DM? DM, like most degenerative conditions has a wide variety of causes and triggers. Genetics of course play a role, with injury, exercise, overall health and nutrition also being key factors. Recent research has identified a mutation in a gene that confers a greatly increased risk of developing the disease. This mutation does not have a simple Positive or Negative test result that can be easily assigned to each dog. Instead the genetic test result gives us a break down of “At Risk to Develop DM, Carrier, and Clear” These three results break down to the following. At Risk dogs have two copies of the gene thought to develop the DM gene. They are at potential risk, but t hat in no way means they will get DM. It means they have the potential to develop DM if combined with outside factors. Carrier means that while the dog caries one copy of the genetic mutation to develop DM they themselves will most likely never have the condition themselves, but they could potentially pass this gene on to their offspring. Clear means the dog does not contain
two copies of the gene BUT still may be at risk if outside factors present. Currently in the US 52% of all Corgis are DM At Risk. 37% are Carrier, and only 11% are Clear. Meaning that a HUGE majority of corgis are at risk for this condition but only a TINY number of those will ever actually develop DM, and most of those will be due to outside factors combined with genetics. OFA recently updated their DM breeding guide to read ” The “A” (mutated) allele appears to be very common in some breeds. In these breeds, an overly aggressive breeding program to eliminate
dogs testing A/A or A/N might be devastating to the breed as a whole because it would eliminate a large fraction of the high quality dogs that would otherwise contribute desirable qualities to the breed.” (An interesting note on this gene that is linked to DM in corgis. This same gene appears in up to 90% of Fox Terriers at risk or Carrier) yet there has never been a single case of DM reported within that breed, which live a very long time. Basically Dm testing is very flawed still! We dearly wish we could get a simple test that says Yes, this dog WILL have this condition, or
NO this dog will not ever develop this condition. But that is no where near the test we currently have for DM. The test results now can say that a Dog most likely will not have DM as long as no outside factors come into play (DM Clear dogs have been known to still develop DM under those conditions) and Dm At Risk dogs (making up the largest portion of the corgi breed) will most likely NOT have DM as long as no outside factors come into play. Of all Corgis (regardless of test results) less than 2% (Current numbers are 1.51%) total will ever develop DM. Which in
itself is a fact that MOST people ignore or do not realize. And also fail to consider exactly how much of that 1.51% is actually due to genetically linked DM and how much is outside factors (bad nutrition, bad exercise, or injury related!)

So our take on DM testing! — Dm testing has a long way to go to be a real tool in a breeding program. Dogs have been reported who have developed DM even when they have been tested as Carrier or Clear/Normal. These diagnoses of DM were confirmed by necropsy and examination of the spinal cord. This study which can be read at Outlines dogs that were tested to have DM while being DM Clear or DM Carrier. Meaning that the DM test result of Clear which is so highly coveted by some breeders, may not be worth the paper the test is printed on, as if a DM Clear dog can still develop DM then the test is worthless. In one case, the dog had a different mutation at the SOD1 locus, which confirms that more than one form of DM exists, and more than one gene is involved. It should for sure be a consideration and lines with known genetically linked DM cases should never be bred. As OFA states, breeders who decide to exclude anything but DM clear dogs in their programs will destroy the corgi breed entirely by doing so. Dm testing is important, but at the same time, it’s one of MANY factors that good breeders should take into consideration. It is not a MAJOR factor. I have spoken to many breeders over the last two years on the topic of DM….I have been offered the chance to own several DM clear puppies. Many from lines that are pet quality at best, or have serious faults or issues that would deem them to be pet quality only if not for the fact that they are DM clear therefore suddenly considered breeding quality! Dm Clear is fast being the #1 concern with breeders, and it’s absolutely silly for that to be the truth! There are SO many factors that breeders should be considering in combination with DM test results, but that they are ignoring instead in favor of getting a DM clear result. Our goal as breeders is to produce the total package. Outstanding health, amazing temperament, super longevity, intelligence, and beauty! The perfect puppy to be a family member or the star of the show ring. A great farm companion or a buddy on your every adventure! We do DM testing on our corgis, and believe that generations down the road the test results will help make a better guide to following and ruling out types of DM (Outside factors causing DM or Genetically linked DM)

Our lines are from lines with excellent genetic health, and NO genetically linked DM or ANY other DM for that matter. We personally have kept At Risk puppies from litters where clears are available, and have recently imported several puppies from Europe with NO Dm testing in the entire pedigree or the puppy. DM is not a concern at all in Europe to date, as several years back a DNA test was developed for a small health condition in another breed, and it almost entirely wiped the breed out of existence, so they are extremely caution about letting small health concerns
snowball into panic attacks that destroy a breed entirely.”

Testing is important. We need to use it to further gain information as to what truly causes DM and how to prevent it. For now, if you purchase that at risk or untested puppy, keep in mind that you are not at anymore risk of DM than purchasing any other puppy. Don’t let DM results strictly define which puppy you buy as it could prevent you from buying a quality puppy.

I feel confident enough in the likelihood of a dog NOT developing DM that I cover this particular disease in my puppy contract. If a dog ever develops DM that was purchased from me, I will gladly replace it with a puppy. It does not matter if the dog tested Clear, Carrier, or At Risk, It is still covered. There are stipulations to this though, as it must be proven through a vet that the dog had DM (only way to do this is post mortem) and I must know that the dog had proper nutrition and care to prevent such things from happening. I will not cover a 40lb dog that has been eating Ol Roy it’s entire life. This is why it’s important to stay in contact with me so that I know your puppy has been properly cared for.

Book by Bobbie Mayer

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