Yes, these things come up now and then and are always widely circulated by certain circles of (the same old) breeders. Funny thing is -- just read the comments by other breeders around such posts and it is quickly apparent that most of these people hardly know a thing about SM, have hardly followed any research, yet are merrily breeding and showing as if this breed health catastrophe doesn't exist. They rush to endorose and share any scrap that they hope gets them off the hook of responsible breeding .
It's another sad attempt by breeders to convince themselves that 1) the SM problem isn't that serious and 2) it is so darn confusing anyway that they cannot be expected to do anything, and now have an 'excuse' not to have to spend a penny on that costly testing and can go back to selling those now more lucrative puppies, and showing their dogs in self-imposed ignorant bliss.
Bingo.I find it interesting that a study of 500+ asymptomatic cavaliers can be dismissed as a mere drop in the ocean in one sentence but in the next her personal experience, based on a very small number of mostly unscanned dogs, are used to argue against a carefully thought out BVA/KC Scheme.
I have watched breeders for almost a decade now complain that research trials were 'too small to be meaningful'. Yet, as Margaret notes, they are more than happy to draw uninformed, unprofessional, anecdotal conclusions based on their own tiny households of dogs or those of their friends. The more the results are not to their liking, the faster they are to start to ask questions about how meaningful the study sample was too (even in the case of the foetal tissue research supported by many breeders -- results were questioned and sample size criticised when results dovetailed with all the other research).
As more and more studies emerged, with larger and larger study samples of cavaliers including a sample of over 500 cavaliers, primarily owned by UK show breeders (a huge sample by any calculation, for a dog-oriented study), the overwhelming evidence remains that the incidence of SM is extremely high in this breed; that most symptomatic SM is strongly correlated to syrinxes, not CM alone; that SM is genetic; that there are definite patterns of inheritance. The fact that some dogs with mild CM sadly have severe pain is hardly disproof of any of this-- rather it underlines what researchers (human and dog) have been saying for some time (if any of these people EVER actually READ any studies ): that one key element of pain and progression in the condition seems to be the individual variation in CSF flow. This is a very poorly understood area but there ARE existing human studies that have shown when flow is analyzed by a special type of MRI in humans whose decompression surgery has not worked well, the discovery is often that the flow is unusual and a fresh surgery that facilitates the kind of flow an individual has, greatly improves pain. I can count on maybe two hands, the dogs I know of with 'mild' CM and no SM that are seriously symptomatic. The vast majority fall into the 'norm' of syrinxes causing problems and as a couple of studies show: width and shape of syrinx are closely correlated to level of pain/severity of symptoms. That doesn't mean there are not rare exceptions. Odd exceptions to the 'typical' presentation occur with ANY disease, *because we are all individuals*.
Also, many cavaliers have PSOM to some degree as well, and symptoms can be very painful and correlate to some being described. Many of these dogs also have enlarged ventricles, which are believed to have some not yet understood role in CM/SM and possibly could initiate pain. And bottom line: I have seen so much totally inaccurate information about individual cases of dogs, including deliberately distorted information, passed around by some (the same old...) breeders to suit their own ends that anyone should be very cautious about claims of what this dog or that dog they've heard about has or doesn't have. I have spoken to some of those US/UK neurologists and some of the actual dog owners and often the information being spread around is simply, wrong.
This claim of breeders being able to breed symptomatic dogs under the breeding protocol is an old canard. It is simply untrue, and such an interpretation raises questions about the intelligence of people claiming this -- surely breeders are not so incredibly stupid and ethically bankrupt that they would ever, knowingly, breed from a dog in pain for ANY reason (diagnosed or undiagnosed)?