Doberman Forum : Doberman Breed Dog Forums banner

Why do health tests vary between breeders?

Tags
dcm
1K views 6 replies 5 participants last post by  dobebug 
#1 ·
I've been researching hard for many weeks following the loss of our adored previous dog and conclude a Doberman would be perfect for us. I've cuddled a few this week that friends own during my research and picked their owners' brains and have had lengthy chats with 3 breeders that sound amazing and are clearly very dedicated to health and are breeding show winning stunning dogs.

The only thing I have noticed is that some of these accredited breeders are not listing any DCM 1 & 2 DNA tests. They list VWD, Hip, Eye but not if the dogs are carriers of the gene that causes DCM. Two carriers mating is very bad news as I understand it? I've checked grandparents etc and see no mention of DCM testing there either...

Can anyone shed any light here please?

Many thanks
 
#2 · (Edited)
DCM in dobermans is likely caused by multiple genes working together in some fashion. The genetic tests for DCM (DCM 1 and 2) merely identify some recently indetified genes which seem to be associated with the condition, but dogs can be negative for either and still develop DCM, or positive for one or both and remain healthy.

A negative test does NOT indicate that the dog or his bloodlines are DCM free. There are no doberman bloodlines which are completely free of the disease.

The research into DCM and its causes is ongoing—it is a complicated disease. The identification of these genes is a first baby step, but at this point, it is mostly of academic interest for breeder to consider as we strive to nail down the causes of DCM.

In the case of DCM, the most important tests to look for are an echocardiogram and a holter test, done on both parents within 1 year prior to the breeding. Even there, the results are a snapshot in time which only show the health of the dog when the tests are done. But eliminating poor breeding prospects based on bad echo and holter tests, and by examining a dog's bloodlines (both direct ancestors and siblings, cousins and aunts, uncles, etc) for DCM and early deaths is the best we can do at this moment.
 
#3 ·
DCM1 (aka PDK4) and DCM2 are new enough that there might not be testing on the grandparents. I guess I had PDK4 tests done when it came out and those dogs are now 12ish, I didn't bother doing DCM2 on them. The reason being that they are 2 genes among probably many that may cause DCM, and they are not particularly predictive, unfortunately. Two carriers may be bad news, it may not be - that's the problem. Dogs that have "bad genes" are living long lives and not developing DCM, and dogs with the "good genes" are dying young, and we still don't know why.

So ... the last bitch I bred had both tests done, and that's the way I would breed in the future but I wouldn't necessarily pay those results a lot of mind. And I wouldn't point the finger at anyone else who didn't either. I would consider them, yes, but I wouldn't make a final breeding decision on them alone. If they were telling us what we wish they would tell us, it would be different. But we have a ways to go on actual helpful DCM gene testing.
 
#4 ·
Thank you MaryAndDobes and Melbrod for explaining the role of DCM1 and DCM2 play in DCM in Dobermans.

I am not a breeder, but I test my dogs for nearly anything for which there is a test especially a gene test. I do this for the benefit of the breeders of my dogs and as general information for people looking for it in the lines of my dogs and of dogs with similar breeding.

Taking a look at the human equivalent of Doberman DCM is pretty enlightening. This is a very similar disease in people. And the medical profession has been looking at it for a long time--to date (I think, the last references I saw claimed this at least) there have been 26 genes which are believe to contribute to DCM in people--this is a polygenetic disease. Even in people where they have found these various genes in people who have DCM there are still people with those genes which are regarded as contributory to DCM who don't have the disease and end up living long lives without ever having DCM.

DCM1 and DCM2 contribute (perhaps) but we don't know how (exactly) and even with DCM 2 it presently is (as far as I know) it may not be a separate gene or gene set from DCM 1--sounds like no one is entirely sure at this point.

The best test for and treatment precursor for is a dog who starts having annual Holters and Echos at between two and three years--and continues to have them since it's the alterations that appear in these tests that give the most realistic information--not long ago I lost a 14 year old male--from excellent lines and although when he died (because I opted to euthanize him because of a non-cardio condition) he had been on cardiac medication for a couple of years, he did not die from cardio and he was going along quite well on meds which he responded to well.

It's really important to bear in mind that DCM 1 or DCM 2 do not "cause" DCM--they are genes that have been found in dogs genetic profile but we are a long, long way from identifying "a" gene of a couple of genes that cause the problem.

So along with asking about the Holter and echo's a hard look with the help of the breeders you are talking to about the background of the dogs who produced the parents is really important not the DCM1 and DCM2 results.

Today there is no test for DCM like there is for color or vWD or several other disorders. And there probably won't be any time soon. The disease is very complex--by comparison vWD is a very simple disorder and easily tested for.

Good luck in your search.

dobebug





I had tested him for DCM 1 (when it was still known as PDK4) He was negative but when the DCM 2 test was available to the public (not just to those who were part of test group) there were already questions about it's importance in the greater scheme of things so I opted not to test. My 14 year old had been tested from just over 2 until he was 8 at least once a year by a cardiologist with a Holter and and Echo--and from 8 until he was 14 he was tested twice a year.
 
#5 ·
Thank you for these excellent detailed answers. Much appreciated.

I had asked a (clearly fantastic) breeder and the answer she gave was that to her the 'proof of the pudding' was far more important. The longevity of her dogs was excellent way down the line as she knew them over 6 generations and similarly chose mating partners with a lot of background knowledge on them and their lineage and longevity. She said it was a far better of 'survival of the fittest' selection than DCM gene testing as it was 100% real and practical. I'd completely agree, obviously.

I remain a little puzzled why a £50 test that may help avoid a mismatch is not being taken though. Will only add to information and knowledge - as incomprehensive as it is?
 
#6 ·
I also would be much more interested in the longevity in the pedigree, and current Cardiac ultrasounds (echos) and 24 hour holter monitors. Even with good longevity, I still want to see the mentioned tests. Cardio is in every line and can pop up at anytime.
I give no real credence to the DNA cardio tests - nice if the did them, but I just don't consider them that important.
 
#7 ·
That would be a ditto from me, Mary Jo,

Because the end results for dogs who have tested positive or negative for DCM 1 or 2 doesn't always correlate with the actual appearance of DCM in offspring it remains (to me anyway) something I might do for the benefit of researchers into the DCM issue in Dobes but I sure wouldn't be using it to make breeding decisions.

Neither test as the research stands right now seem to indicate anything except the fact that DCM is a polygenetic disease--and we knew that already. But like Mary Jo i'd regard a pedigree full of long lived dogs to be more important by far than the two DCM tests that we have now.

dobebug
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top