I can vouch that Sandy has put a lot of time and thought into her breeding programme and she expresses many of the difficult choices breeders face. I value that input.
I think some folks are misreading posts though and thinking they are being targetted when they are not, and when comments are actually being directed at third parties. This curious and theoretical case doesn't need to be made personal.
Back to whether this 'case' actually exists? I have my doubts and have good evidence for doubting it. If, however, it does, then it would be a sad and shocking example of how breeders who could make major contributions to finding solutions to this horrific breed health problem by working with researchers with these dogs' MRIs and pedigrees, instead are willing to block progression and find reasons why they and others won't do anything at all. That, if it were to be the case, is disgusting.
Sarah Blott's work addresses quite thoroughly the issue of diversity and retaining as broad a working gene pool as possible -- and she believes it IS quite broad. If there's a lack of understanding of this point, maybe the US Clubs need to get her over to speak to groups and post detailed information about her research and EBVs and what is needed from breeders for these to work -- because she has discussed all these issues, she has explained that breeding with EBVs helps breeders avoid other bottlenecks, and so on. Maybe the international clubs really should start working *together* on this issue?
An MRI is indeed a snapshot in time but a heck of a lot can be seen and predicted in such a snapshot. An auscultation is also only 'a snapshot in time' yet I have never heard breeders who are working to minimise MVD say there's no point in auscultations as things could change in future.
Statistically there's always a possibility that two badly affected parents could produce perfectly clear offspring. But statistically the odds are far more likely that these two dogs will develop syrinxes over time and perhaps, like the parents, have a form of SM that progresses slowly at first then becomes devastatingly bad.
More MRIs of older dogs would help researchers to better understand progression and answer some of these questions.
At the same time, if breeding cavaliers to minimise SM only brings out other problems,
then truly the viability of the breed must then be questioned. There is no justification to continue breeding just in the hopes that some dogs won't have such problems and allow serious heath problems to be 'just a cavalier thing' that means dogs suffer and die.
but going back to Sarah Blott -- these are ALL issues she addresses and she is optimistic about maintaining diversity and addressing these health problems. But breeders will have to be a key part of getting that information in to the researchers that enables these projects to succeed. Hoping everyone else will do the work and submit the information -- or worse, hiding bad scan results in the hopes that one can prop one's own lines while as a consequence allowing SM to expand even further -- is morally and ethically bankrupt.