Dobermann Breed Health Co-ordinator mid-year update

After substantial time was spent opening a bank account for health funds, HSBC managed to cancel it and we have now started over again. We’ll get there in the end!

If you don’t read anything else in this report, at least read about the exciting development regarding titin below.

Breed Health and Conservation Plan

I had a meeting with the Kennel Club in August to review this one year on. We have updated it without changing the priorities, which are still dilated cardiomyopathy (DCM), cancer (especially lymphoma and mammary tumours), and Wobblers.   Vestibular deafness (DINGS) and hypothyroidism were also flagged.

DCM

I 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

There have been interesting developments in most of these areas.
 

Can we prevent it and can we predict which dogs will get it? A really exciting development

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 un-sustainably and almost certainly introducing new health problems.
Most of you will know about the PDK4 gene identified in the USA by Dr Kate Meurs. Unfortunately, even in US dogs this seems not to be giving any usable level of prediction, and it has been shown not to be significant in UK and Euro dogs. Dr Meurs has now published her paper on the second gene she found and this looks much more promising. Titin 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.
 

I raised with Dr David Connolly at the Royal Vet College about whether this can be validated in UK dogs and we have put together a proposal for a project to test 50 UK dogs to see if it is significant. It’s early days, but this could be the first step towards any useful genetic contribution to breeding programmes.

I will probably be looking for the health funds to contribute a small grant towards this.

There has also been a recent paper suggesting an autoimmune role in DCM. This is really, really difficult to understand, but it may be that there is an autoimmune effect that builds on the genetic susceptibility to DCM. If that were so, then the presence of the autoantibody could possibly be an indicator of later DCM. It could also be removed, but currently only by removing the blood, treating it and replacing it – a logistical non-starter. But there may be something there for the future.

Can we diagnose it early?

Yes, as we all know, 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.

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 three-year 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 so that the dog did not die of it and should live a full life without heart failure. The researcher has now started work on this and I am hopeful that there might be an early clinical trial towards the end of the project. The dobermann community raised £8000 towards the cost of a piece of equipment that will improve the project and this is being tested as I write. Of course, this project is research, and so by definition might not work.

If the autoantibodies mentioned above could be deactivated by a drug, then that might be the start of a cure, but that’s speculative and would be a long way ahead if so.

There is a small project at the Royal Vet College that we have sourced dogs for that is taking a preliminary look at a protein called c-met that is involved in human heart disease. We arranged for affected and (hopefully) unaffected dogs to go to the RVC last year and this for testing. The team took a small amount of blood for the test and owners also got a free echo scan as part of it. If there seems to be any correlation, then the team will apply for a grant to research it further. It is possible that there could be a therapeutic outcome from this, but again a long time in the future.

Estimated Breeding Values (EBVs)

I’ve mentioned before about EBVs in terms of being able to predict whether a dog is more or less likely than average to produce DCM pups. These are currently used for hip and elbow scores. Hip dysplasia, for example, is about 40% genetic and the rest is due to external factors. So, a dog’s hip score is not necessarily a good predictor of its progeny’s hip health. However, there is a genetic component, so if you look at the hip scores of the dog and all its known relatives, you get a better idea of the genetic risk. EBVs are presented as a variation from the breed average and the point is not to be a stick to beat people, but to be a tool whereby the owner of a dog with a high EBV can look for a low EBV mate.

I am liaising with the Kennel Club and the Roslin research group to see whether we can get a database set up and built on over time for this. It’s a huge project.

Longevity

The Kennel Club’s 2014 survey (100 dogs) gave longevity at eight years. My own database, currently with about 350 dogs, gives a mean of 9.2 years and a median of 9.8. Almost half had died before their 8th birthday, and about 15% before their 6th birthday. Please keep sending me details of your dogs (email address at the end of this report). I just need pedigree name, date of death, and cause of death if you are fairly confident of it. I need to get to about 500 to obtain really good data.

Changes to ethics

The ten clubs agreed two changes to the Assured Breeder Scheme recommendations. These are:

  1. To add a recommendation that bitches should not be bred from before the age of two. There is currently nothing in the dobe recommendations, but a lot of breeds do have this.

  2. That eye testing should be carried out once before breeding and once at age 8. The initial test will pick up PHPV as well as other disorders. The repeat test will give the Kennel Club a better picture of the prevalence of other disorders such as PPM and cataracts, which are thought to be more prevalent in dobes than in many other breeds. The current recommendation is for annual testing, which very few breeders do, so this is a reduction in the burden on breeders

     

  3. The Kennel Club have recommended putting the eye test application on hold as they are working with the BVA to review all such tests and may well come up with a similar idea themselves. At my recent meeting at the KC I was told that applying for an ABS recommendation not to breed bitches before two years of age would require evidence that earlier breeding is harmful. If anyone has access to any evidence on this, please let me have it.
     

All the clubs have also added to their Codes of Ethics that owners must ensure vWD and other test results are entered on the dog’s record at the KC. This is particularly necessary for vWD as there are now multiple test providers and it cannot be guaranteed that the test provider will do this.
 

Sue Thorn

Breed Health Co-ordinator

suejthorn@yahoo.co.uk

August 2019