OFA DM test stats. - Page 1

GERMAN SHEPHERD DOG
CLEAR	78	49%
CARRIER	50	31%
AT RISK	31	19%
TOTAL ABNORMAL	81	51%
TOTAL TESTED	159

Most recent OFA DM test stats for GSDs.   Almost half of gsds tested have tested clear.   Only 159 tested.

You might want to explain this test...A lot of new people to gsd do not know what this is for or why.

http://www.offa.org/dnatesting/index.html

http://www.caninegeneticdiseases.net/DM/ancmntDM.htm

I had to put a dog down because of DM and watch what the disease does it is awful to say the least.
The testing is a super tool.  But now how do you get breeders to use and not breed to the carriers?
And if the dog is a carrier or at risk will it throw to its pups is bred? The obvious answer to me is not to breed those at risk or even carriers.  JMHO!

However, having watched an amazing dog crippled but still dragging himself around to follow my everystep was heartbreaking and really if DM could be stopped or even reduced from the population that would be tremendous!

 

I would rather pay double or even triple the normal amount for a puppy, knowing that the parents have been screened for DM, hips, elbows, cardiac, thyroid, CERF and Epi. I've had my share of bad luck and heartbreak, therefore I have become extremely paranoid in my search for a new dog/pup.  I haven't found one breeder so far that screens for all of the above in  both parents

The reason Starrchar you have not found a single breeder who screens for all the conditions you mention, or others that plague the breed, or canines in general, is that most of these conditions do not have reliable and DEFINITIVE tests to be able to predict outcomes. EPI for example, is almost certainly a defect in genetic expression for certain enzymes. But it is highly unlikely that it will be found to be a simple autosomal recessive gene responsible for all cases. Further, many cases are misdiagnosed. It may also well be that certain environmental stressors, such as infections, parasitic burden, or other illness, also can wreak havoc in whether proper enzymes are produced, thus confounding the genetic situation where, in fact, proteins coding for specific enzymes are faulty. We see complex situations in humans where particular enzymes are produced in lesser amounts, or not at all, depending on a variety of factors.

Secondly, in some cases of the conditions mentioned, it is highly likely that environment does play a part. Third, if most reputable breeders, of any breed, utilized genetic screening, it is still unlikely that any condition could be completely eliminated because the overwhelming number of people who breed dogs are people who just put two dogs together without any concern for what is produced.

Even if a genetic test is available for a specific condition, one must ask whether eliminating a particular dog who is positive for that condition is, in fact, a reasonable idea. A question that everyone should ask is what are the qualities we seek in the GSD. As it is, we have almost ruined temperament in certain bloodlines, ruined working ability, structure, and certainly compromised health. There are already bottlenecks in the genetics of all these breeds being manipulated by humans. There are even bottlenecks in human pedigrees. This bodes ill for such organisms.  The number of genetic diseases that can be tested for accurately in humans, for example, are many. They are not used at all until there is a problem, in most cases. Finally, spontaneous mutations do happen, so one can never be rid of all conditions, at this stage of human or canine history, even if they were simple genetic defects involved.

The test used for DM is not a definitive test.  The researchers who developed it cautioned about how results should be interpreted. The fact that it was done on so incredibly small a sample of the breed should give any reasonable person pause for thought if they have the slightest understanding of statistics, testing, genetics, etc. And the fact that it is no longer available may mean it is not a strong enough test in what it tells us for any commercial lab to bet their ass on it paying for all the work it will take to make it available to the public around the world. Just because someone claims an association with a specific disease and some genetic test does not make it so, or mean the test is reliable enough on which to bet the farm.

Just food for thought on this Sunday.

Hodie, Thanks for your response. You make many good points, but still wouldn't  it be better to do the screening so we could start somewhere?  I just think if  we had the opportunity to look at a pedigree and go back at least three generations (yes, I know that would take a decade or so) to see what health issues the dogs had, at least we'd be aware. It would only work of course if ALL dogs were screened and it was mandated by the various registries in order to register puppies. It just seems there's got to be a way to start producing healthier dogs and the screening is the best we have right now.  I commented on a few of your remarks below. Please understand that I am not arguing with you- just discussing.

EPI for example, is almost certainly a defect in genetic expression for certain enzymes. But it is highly unlikely that it will be found to be a simple autosomal recessive gene responsible for all cases. But, some will be found and at least we'll know about it. Further, many cases are misdiagnosed. It may also well be that certain environmental stressors, such as infections, parasitic burden, or other illness, also can wreak havoc in whether proper enzymes are produced, thus confounding the genetic situation where, in fact, proteins coding for specific enzymes are faulty. THen a retest may be in order at a later date. We see complex situations in humans where particular enzymes are produced in lesser amounts, or not at all, depending on a variety of factors. I understand that the screening is far from 100% fool proof, but we've got to do something!  My mother has ovarian cancer and was just tested to see if there is a genetic component. Her test came back negative- she doesn't carry the gene most commonly associated with breast and ovarian cancer. I know that doesn't mean I'm home free though. Since she has the ovarian cancer, my risk of getting it is still greater than the average woman. BUT, it's not nearly as great as woman whose mother tested positive for the gene. There's more to this I don't want to get into it too much.

Secondly, in some cases of the conditions mentioned, it is highly likely that environment does play a part. Yes, but that doesn't seem like a logical argument to refrain from screening at all.  Third, if most reputable breeders, of any breed, utilized genetic screening, it is still unlikely that any condition could be completely eliminated because the overwhelming number of people who breed dogs are people who just put two dogs together without any concern for what is produced. You sure are rioght about that, but mandatory screening would certainly stop that nonsense!

I'd love to hear back from you- I do agree that the screening is NOT going to solve all the problems! I also think  that even if the testing was 100% reliable and even if the various breed registries wanted to do mandatory screening there would be too much of an outrage from breeders for it to ever come about. 

Char

 Char,

I think you miss the most important point of all in what I wrote. So far, there are few actual screening tests which predict with 100% reliability any condition, in humans or canines. I am NOT arguing at all against screening, nor am I arguing that genetic research should not be done and screening tests be developed. I am saying that for now, they are not available in most cases. And I am also saying that if research is misunderstood and misquoted, and used inappropriately, it does not help anything. If screening tests are available, and if they are REALLY valid, of course, they should be considered. But for many reasons, it is unlikely to happen that most breeders will screen their dogs. For one thing, as you mention, the registries don't make it a requirement. Secondly, it is costly. Thirdly, even with a positive screen test, it will often NOT mean the human or animal will develop some condition. And again, in any litter, with simple autosomal recessives, for example, there will likely be babies or pups born who are neither carriers, nor affected at all. So my main point is that one cannot think about this in black and white terms.

I am sorry to hear about your mother and I hope the condition was discovered quickly enough that she can be successfully treated. As far as your real risk, I think the fact is, no one really can predict your risk. Neither is worrying about it going to be particularly productive, although I understand why you would worry. The important thing is for you to be proactive and make sure you get appropriate health screens.

As far as screening for specific human cancer genes, it is a very, very complex situation. Just because one has a given gene does NOT always bode for the development of disease. There are broad ethical issues, as medical issues, involved as well. For example, should someone who possesses a certain type of gene found in breast cancer elect to have a mastectomy long before any disease ever shows up? And should people who have a particular gene, for example, be denied medical insurance or a specific kind of work? My point is that we must not throw the "baby out with the bath water".

Mandatory screening will not stop people from breeding dogs, anymore than mandatory screens in humans will prevent humans from having babies when they know there is a high likelihood a child might be born, for example, with Down's Syndrome. Further, genetics is not so simple and black and white as so many think it is having only learned about Mendelian genetics.

I hope this clarifies what I wrote previously. Further, whether we like it or not, life happens and it is not always fair and it is not always pretty or pleasant. Each of us struggles with what we make of it, including the parts we don't particularly care for.