Dobermann Breed Health Co-ordinator end-year update
This update is taken from Sue Thorn's end year update to clubs to provide to committees and members and for dobermann owners generally.
A reminder that several clubs carry out biomarker testing at their champ shows. Midland Dobe Club arrange reduced price echo and Holter testing for members. Several clubs also now provide Holter monitors at a reduced rate to members, including SEEDC, WDC and SWDC. Check the club’s web site in each case.
Breed Health and Conservation Plan
A reminder that we have this plan, developed with the KC. The priorities are dilated cardiomyopathy (DCM), cancer (especially lymphoma and mammary tumours), and Wobblers. Vestibular deafness (DINGS) and hypothyroidism were also flagged.
The Kennel Club’s 2014 survey (100 dogs) gave longevity at eight years. Sue Thorn’s own database, currently with over 650 dogs, gives a mean (average) of 9.3 years and a median (middle value) of 9.9. Thus, almost half had died before their 9th birthday, and more than 1 in 7 before their 6th birthday. Please keep sending Sue Thorn details of your dogs (email@example.com), with pedigree name, date of death, and cause of death if you are fairly confident of it. The mean figure hasn’t varied for some time and is probably fairly accurate, at least for the dogs in the database, which are mostly from show backgrounds.
Sue would like to thank the following breeders who have kindly sent me their full longevity records:
Aritaur, Baikel, Jojavik, Kodam, Lateagain, Lodgehouse, Martifers, Newfords, Philmont, Remesca, Roanoke, Swnydwr, Woodbriar, Zeloviak.
It is important to always think of any disease from five angles: can we prevent it; can we predict which dogs will get it; can we diagnose it early when they do get it; how can we manage it; and can we cure it?
Can we prevent it and can we predict which dogs will get it?
These two go hand in hand and usually require a genetic test. The two problems here are that it cannot be a single gene, and also that, even if it was, given the prevalence, removing all affected dogs from breeding would mean removing at least half the population and thus reducing the gene pool unsustainably and almost certainly introducing new health problems. Most of you will know that the PDK4 gene identified in the USA by Dr Kate Meurs has been shown not to be significant in UK and Euro dogs. Titin a large protein that plays an important role in skeletal muscles and in heart (cardiac) muscle) looks more promising, not least because it is known to be involved in human heart disease. Again, it won’t be the only gene involved, but it may be a better candidate for suggesting avoiding mating two dogs carrying the variation.
Sue Thorn is currently involved in a project to test UK dogs to see if Titin is significant. Sue has arranged so far providing cheek swabs from about 20 dobes, roughly half with DCM and the rest tested clear at 5 years of age or more. The RVC team now also have access to blood from the PROTECT trial and awaiting further information about testing. As mentioned above, this will not provide a simple answer even if it is deemed to be significant, but it will increase our knowledge.
Can we diagnose it early?
If we test our dogs regularly, we can spot DCM in its ‘occult’ or hidden stage before there are any visible symptoms. This makes it more likely to be susceptible to successful treatment to extend life and delay the onset of congestive heart failure or sudden death. There have been many reports now of dogs living 4 or 5 years of healthy life post diagnosis due to these drugs and it makes very clear the importance of annual heart checks. It also avoids mating dogs that have hidden DCM.
Dr Dukes-McEwan’s paper on biomarker testing has now been published and funds were raised by the health clubs to make this available by Open Access. The paper concludes that biomarker testing is a reliable first line of test for DCM, provided the dog is referred for echo and Holter if the results are elevated. She recommends moving on to echo and Holter at slightly lower levels than previously recommended, 0.056 for HS Troponin I (rather than 0.07) and 621 for NT-pro-BNP, rather than 735. The paper is available at (https://onlinelibrary.wiley.com/doi/full/10.1111/jsap.13455).
When contacting your vet for biomarker testing, please ensure they send the samples to IDEXX, as this is the only laboratory that can carry out high sensitivity Troponin I testing, measuring down to 0.001 ng/mL. Other labs can only test down to ‘<0.2’. As the cut-off for suspected DCM is 0.07, this means a result of <0.2 can never be used to say the dog does not have DCM. A result of 0.2 or higher means the dog possibly has DCM and should be echo/Holter tested. Thus, there is no possibility of ‘clear’ results from such tests.
Can we manage it? Can we cure it?
At the moment management is by means of vetmedin and other drugs, which are very successful at prolonging life if started early.
We also have the ‘How to Fix a Broken Heart’ project with Dr Connolly at the RVC. This is a research project into the potential for cardiac stem cells from healthy dogs to be injected into DCM dogs to reverse the symptoms. If successful, it would require regular injections, so it is not a cure, but it would manage the disease. The project was delayed by Covid and so far it seems, sadly, that it may not offer the answer we’d hoped for. However, it will be a while before the project finishes.
In the database, over 5% of dogs with a recorded cause of death were due to Wobblers. This is behind only cancer, DCM and age-related issues. EMBARK in the USA are carrying out a research project to try to identify any relevant gene(s). Some UK dogs were recruited to this, but do not yet have any further results.
Degenerative Myelopathy (DM)
Sue Thorn was contacted by a Dobermann owner asking why genetic test results for DM are not accepted by the KC. This was taken up with Hannah James at the KC. It seems that, while DM is autosomal recessive, it has incomplete penetrance and, in Dobermanns, there is no link identified between the genotype and the clinical likelihood of developing DM. The gene probably shows a predisposition, rather than a definite problem (rather like type II diabetes), and there may even be another, protective, gene in some cases.
KC and health testing
Eye testing for ABS breeders is now only required once, prior to initial breeding.
If you carry out vWD tests, please check whether the company you use automatically sends the result to the KC, and send it on yourself if not.
We really do need good records on this.
A number of owners have been sending hip x-rays to Australian vets, who usually return them within a day or two, especially while the BVA had huge delays. The KC will record these values if sent them, but do not add them to the dog’s visible record. The KC did say they were going to test whether UK and Australian results were comparable, but they did not have enough results and I believe they have abandoned this.
Breed Health Co-ordinator