Information on DM or Spinal Myelopathy in GSD's

ROSEHALL KENNEL

Sparta, Tennessee

 
emilyroberts@frontiernet.net         
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Rosehall Kennel uses the results of genetic testing to guide it's breeding program to ensure that there is no chance of our puppies contracting degenerative spinal myelopathy.  The following link gives a relatively simple explanation of the condition and also has a good explanation of the genetic link for the condition and how careful breeding can eliminate the risk of a puppy having this problem later in it's life.   http://en.wikipedia.org/wiki/Canine_degenerative_myelopathy  We are seeking copyright permission to publish more detailed information here . . . check back with this page from time to time for more information.

 

Thank you Dr. Clemmons Re: copyright permission   Tue 12/6/2011 6:56 AM  http://neuro.vetmed.ufl.edu/neuro/DM_Web/DMofGS.htm

The web site at UF will be closed shortly, so the link may go bad. It will come back on an educational, commercial site a bit later. I still believe the web should be for free real education, but I guess I got outvoted! The rule is only that it be free and that it is still best to link. Here is what we tell people who inquire of us about GSDM...

Unfortunately, we cannot offer the DM Flash test at this time except for research purposes. We have included information about the test and our typical workup for informational purposes as the information is still correct. 

New information is that we may have a genetic test for the disease. We can run the test for people, knowing that it may be negative in a number of suspect cases, since up to 75% of those with clinical signs actually do not have GSDM. Your veterinarian can help you with this by collecting the blood and arranging to send it to us. We will provide the results within 2 weeks. We still feel it should not be the sole diagnostic run for the disease, but it may go a long way toward confirming the presence of GSDM.

The DM Flash test is not a good screening test for this reason…there are too many false positive results due to a high incidence of the change in the breed while only a limited (10-20%) of the positives get the disease. However, that said, it does say that the risk of developing GSDM is 12 times higher in dogs who are positive on the DM Flash test than in dogs who are negative. A negative test suggests there is a 99% chance the dog will not get GSDM. However, a positive test in normal dogs has only an 11% predictive value.

In dogs with clinical signs of possible DM, the DM Flash test is a good diagnostic test. It is 96% sensitive and 99% specific and is generally going to separate those who have GSDM from those who do not have it (only some other neurologic disease). It still does not replace other tests since there may be more than one disease, but it probably is sufficient to confirm the diagnosis of GSDM and move the patient to the “probably GSDM” category. What this means is that a positive DM Flash test means there is less than a 1% chance the dog does not have DM as part of the clinical picture, while a negative DM Flash test means that there is a 4% chance that the dog may still have GSDM even though the test was negative. With a negative result, only additional tests can be sure that GSDM is part of the disease process or whether another disease is more likely.

So, while 91% of the proportional risk of developing GSDM is accounted by having a positive DM Flash test (genetics accounts for most of the reason the patient gets GSDM). A positive test in a normal dog does not mean they will inevitably get GSDM; just that they are at a greater risk. A negative test means it is highly unlikely that the dog will get GSDM, but not impossible. That is about as good as any test. Those who test positive are the ones who should be watched and extra care taken with. We may ultimately find out what other factors influence the genetics to lead to GSDM and then we might be able to prevent the disease from happening. For now, all you can say is there is a risk of developing GSDM and that might be a reason to alter breeding, but only if other things are factored in as well.

Like families of MS patients, there is a risk that others might get MS because of increased genetic risk. In dogs other than German Shepherds, the DM Flash test may mean the same, but we do not have enough data to say that. As such, we would cautiously recommend that other diagnostics be performed in order to be sure the results are accurate. While we expect that the results of the DM Flash test to be similar in other breeds, only more numbers of patients and studies on randomly-sampled dogs from that breed will answer that question.

Thank you for taking the time to email us about our program on German Shepherd Dog Myelopathy (GSDM). We have studied this disease over the last 30 years and continue to do so. Our current program is unique and designed to improve the diagnosis of GSDM and offer a sensible treatment for GSDM based upon what we know of the underlying cause of the disease. Unfortunately, we cannot answer specific questions about patients that we have not seen. The Internet is not sufficient to establish a valid client-patient-veterinarian relationship. We have offered our web pages (http://neuro.vetmed.ufl.edu/neuro/DM_Web/DMofGS.htm) as a guide and educational resource for people who think their animal is affected with GSDM. There is a lot of mis-information on the Internet, we have tried to provide some sense to that. The information on our web site is what we can currently offer and recommend to those patients we have not seen. Our web site is where you can start. Yes, we have looked at many treatments for GSDM, but what is on the web site is what we have found to help most of the GSDM patients we see. Older versions of our information have been replicated at other sites on the Internet. Our pages are officially what we recommend and do. From our work and the genetic data available on GSDM, we believe the evidence says that GSDM is an animal model of Primary Progressive Multiple Sclerosis in human beings. So, at least, we think we know what GSDM is when we separate those who do have it from those who do not.

Part of our program is the diagnosis of the condition. Unfortunately, it is correct that the only current method to be absolutely sure is with a necropsy, which does not help patients before death. We have established criteria that help us make accurate diagnosis. I think that we do better than what has been reported by some authors. Only 25% of the patients enrolled in their study were found to have the disease. The complicating factors which confused the diagnosis in that study would have been found by our criteria. So, what do we do. Basically, they are routine clinical test, but applied in a specific sequence to help us find out all of the patient's problems. First, is the clinical examination. That includes looking at who the patient is. If the patient is a German Shepherd, then there is a higher probability that a chronic progressive spinal cord problem might be do to GSDM. If it is not a German Shepherd, it may have a myelopathy, but it may be from another cause. We are not sure that the disease in the Corgi or in the Boxer is related to the disease in the German Shepherd. On the other hand, we can distinguish the disease that Corgis, Boxers and Rhodesian Ridgebacks get from GSDM based upon genetic aspects that these breeds have that related to their form of DM. Since these diseases are genetically different, applying our treatment to these breeds may not do any good. The second criterion is based upon the EMG (electromyogram) which evaluates the muscle-nerve connection. The EMG and all peripheral tests of neuromuscular function are normal in uncomplicated GSDM. On the other hand, the spinal cord evoked potential evaluated over C1 is abnormal in GSDM. This indicates that there are problems in the white matter of the spinal cord. We also look at the difference between the cerebrospinal fluid (CSF) collected from the cisterna magnum and the lumbar cistern. The latter shows elevations of CSF protein without concurrent increases in CSF cell counts. While many of these proteins are inflammatory in nature, one of the ones that can be measured easily is CSF cholinesterase. The CSF cholinesterase is elevated in the lumbar CSF (above 300 IU/ml) in most cases. Unfortunately, this change is not specific for GSDM, only for inflammation (GSDM is one of the inflammatory disease of the spinal cord). Titers for infectious diseases are normal or, at least, do not indicate another disease process. Finally, we look at special imaging to evaluate the structure of the spinal column and whether there is evidence of spinal cord compression from some disease process. This does not rule-out GSDM, rather imaging rules-in complications. The former criteria are what help diagnose GSDM: the clinical picture, the EMG with spinal evoked potential, and the CSF analysis with cholinesterase. The imaging only looks for a surgical disease (or its absence). Depending upon the condition and clinical signs, we do myelography plus or minus CT scan or MRI scans to help us determine whether there is a local compressive disease.

Not every neurologist does the tests that we do. That might be why we have success, since we know better what we are treating and also whether to treat a surgical problem or not. On the other hand, there are other approaches to this disease and you will need to follow what is recommended by those who have seen your dog. You should, at least, see a neurologist and let them help you find out what they can for your dog. Remember that without the proper tests, it is a guess as to what is wrong. You can search for the closest neurologist at http://www.acvim.org/

The other part of our program is the treatment outlined on our web site. It includes exercise, diet, supplements and medications. Each of these has an impact upon health and upon the disease. The components of the treatment work together to reduce the progression of GSDM. They target the processes which we have uncovered as the causes of the pathologic changes we see. We have seen few side-effects (mostly GI upset) in the patients we diagnose and treat. There are things which can happen as rare occurrences when using any drug. If they complications resolve on stopping the drug and return on re-introduction, then it is probably drug related. If your veterinarians feel there is a problem, then the medications should be stopped until it is determined whether they are the cause or not. Many times it is discovered that some other disease is present rather than the medications. All of the medications have been used in dogs for many years (not just for treating GSDM) so they are not new. Only the application is new. N-acetylcysteine is the newest and we have used it for over 10 years. On the other hand, we do not like to use medications unless we know what we are treating. So, we do not treat without reaching a diagnosis. The 2 parts of our program, diagnosis and treatment, work together. We diagnose early and treat early, which is why we have success. In the past, most patients progressed to posterior paralysis in 3-6 months. This would progress to all 4 legs in another 3-6 months with death from brainstem failure (in those patients allowed to progress that far without intervention) 9-18 months from the first diagnosis of GSDM. That has changed now. In our hands, most GSDM patients will remain functional for 12 months, while many outlive their disease.

If dogs respond well to the therapy, they should continue on it potentially for life. However, if their condition is stable for several months (at least 6 months), then decreasing the medication (aminocaproic acid and acetylcysteine) to 2 twice a day on days given can be attempted. If this works as well as 3 times a day and they remain stable for another 6 months, then the dose can be reduced to daily. Some cases may be able to maintain with diet and supplements alone, but most cases will require continuous medication.

We apologize that we cannot help you more. Certainly, we are happy to see patients at the Veterinary Medical Center at the University of Florida (number below) by appointment. If that is not possible, then follow the course that makes sense to you and your veterinary team. They have seen your dog and know it far more than we can via the Internet. We hope that you receive the care and treatment that you need.


RM Clemmons, DVM, PhD, CVA, CVFT

Former CAPT, USPHSR

Aso Prof of Neurology & Neurosurgery

SACS/University of Florida

2015 SW 16th Ave

Gainesville, FL 32608

rmc@neuro.vetmed.ufl.edu

http://neuro.vetmed.ufl.edu

352-392-2235

352-294-9866 (FAX)


On Dec 6, 2011, at 7:23 AM, "Eliot Roberts" <eliotroberts@frontiernet.net> wrote:

Sir:  We raise large GSD’s and are concerned about DM. We use genetic testing of our breeding dogs and never breed a carrier to a carrier and are working towards having DM free breeding dogs.  Our marketing is web based: www.rosehallkennel.com  and we would like your permission to link your 1998 article on DM on our site.  Would also be interested in your recommendations of other articles that you think would be helpful to our buyers.

 

Thanks . . .  Eliot Roberts, Rosehall Kennel, Sparta, TN