View Full Version : Rusbridge Newsletter: head shape study

28th April 2007, 12:23 PM
Clare Rusbridge and Penny Knowler have released a short news bulletin/newsletter, posted here with permission. Kudos to Sandy Smith for raising funds for this research; her book is highly recommended for anyone with an SM cavalier or interested in the condition and proceeds all go towards further research. There's a link to her website in the newsletter. The results so far will be of interest to many of us who had hoped there might be some direct correlation between head shape and incidence of SM but so far that doesn;t seem to be the case.

Please note I have a new URL for my CKCS SM Infosite -- it can be reached at the old url of http://sm.cavaliertalk.com but is also accessble at the easier-to-remember www.smcavalier.com.



A research update
By Clare Rusbridge and Penny Knowler
Stone Lion Veterinary Centre, 41 High Street, Wimbledon, London, SW19 5AU
neuro.vet@btinternet.com (CR) Confidential Fax: 020 87860525
penny.knowler@ntlworld.com (SPK)

The knowledge, experience and support of breeders and pet owners continue to play an
essential part into the research for Chiari-like malformation and Syringomyelia.

Preliminary results of pilot study looking at the possible correlation between
head shape and CM/SM in different toy breeds.

In response to some observations made by breeders on head shape, a simple pilot study
was devised and has been generously funded by Sandy Smith’s ‘For the Love of Ollie’
Fund. Dogs were selected on the basis of head length/breadth ratio, degree of doming and
presence or absence of a ski-slope shape to the back of the head. CM/SM status was
confirmed by MRI. Early results of this pilot study found no correlation, however the
investigation is still ongoing. This study has been a tremendously valuable exercise in
other ways. On the basis of head shape, some dogs had been presumed to be affected and
owners had originally elected against MRI screening. However some of these dogs were
actually found to be free of the condition. This suggests that it is not yet possible to
predict CM/SM by a visual assessment of head shape. It also provided the opportunity to
obtain blood DNA samples for the Genome study in Montreal*. In particular, we would
like to thank Lee Pieterse in Australia for her valuable contribution to this study and, of
course, Sandy Smith in Canada.

The ‘For the Love of Ollie’ Fund and Syringomyelia DNA Research Fund
is continuing to support the identification of
i) SM clear lines of dogs in breeds where CM/SM is emerging
ii) SM clear and affected dogs for DNA studies including association studies to
help identify the gene in the more severely affected CKCS breed.

We welcome both information and financial support to continue this work. Donations
can be made in a variety of ways http://www.fortheloveofollie.com/ and
www.smcavalier.com Donations ‘Syringomyelia DNA Research’

*The genome research aims to:
i) Identify the gene/s involved in CM/SM and how they bring about the
ii) Develop better treatment strategies for affected dogs in all breeds.
iii) Develop a genetic test to identify carriers for breeding purposes to reduce or
eliminate the CM/SM condition in different breeds.

28th April 2007, 06:26 PM
I visited the link for the book "For the Love of Ollie" and if you havent seen it, you should go look it over. As well there is a page for polls which might be helpful to them to fill out. I want to see if I can find the book to look at as it appears quite helpful and well written. Poll page http://www.fortheloveofollie.com/index.php?mod=polls

Edit: So a minute ago I decided to take a look at the links the book recommends for more info. At one of them there is also additional website research links - and who is recommended at a health sm resource? The issue in Karlins post "Well this beats all" All authorities on sm need to review their link suggestion pages from time to time to be sure they still want to hail someone as a health authority I think! Shameful.

28th April 2007, 08:43 PM
For the Love of Ollie is a really nice book and contains many stories of many SM-affected cavaliers, in addition to Ollie. :) I've met Sandy before and have a copy myself.

The links she offers are to all the general cavalier health resources. The website linked to by Sandy would have accurate information though very conservative on SM and it is a bit minimalist given the amount of information now available. (I'm a believer in giving people as full a range of information as possible to let them at least weigh up all the existing evidence as they make their own choices in how to use that information -- or not.) Sandy is not being prescriptive, but offering a range of sources for information.

Unfortunately SM, like MVD or any prominent health issue in any breed, is often a point of controversy and politics and personality conflicts. That unfluences what information, if any, is made available, by whom, and its tone. It took a very long time for MVD to be acknowledged as a widespread issue and many who were involved in that experience say the same pattern is happening with SM. SM is a complicated issue as well; breeders are faced with few answers, many difficult choices and also are left trying to balance good hearts against possibilities of SM; and to conserve the best genes they can in the realisation that making choices in one area often can have unwanted results in others. It would be much easier if either MVD or SM were straightforward, single-gene conditions as that is easier to isolate but both seem to be polygenetic, making it virtually impossible to eliminate (but hopefully, possible to constrain, reduce the level of seriousness, or age of onset).

I do understand breeders having difficulty in choosing the best path for their own breeding programmes and weighing up how to proceed and there are many different opinions on what to do and some of the options can be costly.

However, I don't understand being misleading, suppressing information or simply not bothering to supply it.

28th April 2007, 10:11 PM
Oh I think our own health care system for ourselves is wrangled with these issues too - or so the winding road I am currently on makes me think so.

Perusual, I type half of what I meant leaving a big space on what I really meant (lets call it stress).

The link was not at the book site (sorry if I implied that) but rather on another site I got from the book links. My point was not to insult those providing links but rather suggest those that do, need to update/re-evaluate the sources they supply. If you trust an authority you will trust who they refer you to. In my own thinking that stems from the fact I update websites and know how easy it is to put up such information and not look back.

29th April 2007, 10:19 AM
Im one of the ones who hoped that the Head Shape of the New Look Cavaliers just maybe could have had a link in the SM Cavalier Problem ,but it looks like that avenue is a no-no .

That reason seemed to me to be making sense ,

The alteration of the shape of the Cavaliers 'Heads in the early 80's ,the appearance of SM in Cavaliers about the same time ,there just seemed to be a connection,but I guess not

There now seems to be something nasty ,that no-body knows about lurking somewhere which could be more of a worry than if it had just been as simple as the alteration of the Head Shape

Until this is discovered ,and maybe its a couple of genes that have mutated ,it could be quite a long time till this is found out about ,then the only thing that can be done at the present ,is for Cavalier Breeders to MRI their Breeding Stock for a Syrinx to be present or not

Karlin is so right when she mentions that at the beginning of MVD appearing in the Cavalier Breed ,there was such a lot of opposition from many Cavalier Breeders ,infact two highly respected Gentlemen ,one a Geneticist ,who were trying to help the UK Cavalier Club in the problem gave up in despair!

It could be History repeating itself in the SM Problem ,and Ill say again ,that its with the help of the Cavalier Pet Buying Public , only to buy Cavalier Puppies from Breeders who have MRI Scanned their Breeding Stock ,that theres a chance that the SM disaster might be being averted ,till the Researchers can find an answer to the SM Problem


29th April 2007, 10:43 AM
They are continuing to gather information, Bet, so perhaps a correlation will gradually appear. It seems to me like a connection could be there too, but often with genetics (or science generally) the things that seem likely or where there seems to be a common sense reason for something, turn out not to be the issue. It can be really frustrating.

One slightly more indirect way in which your ideas could well be correct is: while it may not have been a specific size or shape of head, it may well be somethinbg more subtle -- as in some overall appearance that people selected for. Some of the pedigree work sems to indicate that the overuse of a range of studs has really dispersed the SM genes as they father so many hundreds to thousands of puppies and are so influential in the direction the breed goes. So people were selecting for a certain look from certain studs, and those were the dogs the judges were putting up as champions. Perhaps wholly coincidence as well however.

Lines that were not influenced by those studs seem to be potentially less affected -- but all that remains to be verified.

The good news from this study though so far was finding more A dogs for breeding. :) I hadn't even known they were doing this work (further proof that I am not privy to or hiding researcher secrets!! :lol:).

29th April 2007, 08:14 PM
finding more A dogs for breeding. Curious - was that a typo or A dog refers to a certain type of winner, as in A circuit (old horse show rider so I am thinking the A, B thing here).

24th May 2007, 08:05 PM
The alteration of the shape of the Cavaliers 'Heads in the early 80's ,the appearance of SM in Cavaliers about the same time ,there just seemed to be a connection,but I guess not


SM didn't necessarily 'appear' at the same time. Diagnostic techniques and enhanced communication mediums mean that as with many disorders they were probably always there. Merely the ability to detect them and a uniting of the interested parties has highlighted it. Just think how many 'new' disorders we know about....they aren't new at all.

24th May 2007, 08:21 PM
It isn't a typo; it refers to 'A' dogs -- dogs that are graded A under the scanning and breeding guidelines that were unanimously approved by the international researchers attending the first SM conference in London in November.

SM didn't necessarily 'appear' at the same time. It did in any visual sense, which is I think what Bet means (having had many discussions with Bet on this issue). Bet, who has been around the breed for many decades, would be aware that SM may have been around in milder form for some time-- the guess is that the gene goes back to two very early foundation bitches from the 50s -- but in symptomatic terms no one was seeing what they called the 'scratching disease' in any numbers until the 80s and een then no one connected it to anything as serious as SM until the 90s. Many old time breeders do remember seeing it in the ring by that time but not earlier, as far as I know. So for all intents and purposes the 80s are indeed when it would have literally 'appeared'. :) 'Always' as in, they were 'always there', may have a pretty limited application as well, I suppose. The breed has only existed as a reconstructed breed since around the early middle of the last century and unfortunately it seems a couple of the few foundation dogs left after WWII were carrying the genes for the malformation that can produce SM. That weighted the whole breed towards developing it, it seems. :(

Neurologist Geoff Skerritt in the UK told me the first example he saw of the skull malformation was an xray in the late 70s or so, but it wasn't until much later that he could connect it to some of the symptoms people were seeing by the 80s.

24th May 2007, 08:38 PM
It did in any visual sense, which is I think what Bet means

Would seem odd to connect it to the head shape change at the same time if only meant in a visual sense. As you quite rightly say this is a relatively young breed and the connections would only be made as the affected communities were able to come together with improved diagnosis and communication.

24th May 2007, 08:43 PM
What a lot of the breeders have been wondering is if a change in the shape of the head that breeders themselves were selecting in the 80s conributed to a more severe form of SM; eg somehow also seleceted for more sever forms of the malformation or a shape that especially obstructed CSF flow and caused syrinxes... the 80s are a time when some like Bet who remember the heads from well back, think there was a noticeable shift. Not all agree and researchers have so far said they see no correlation in head shapes, when they do lots of measurements on MRIs.

If it were linked to head shape it would make it a lot easier for breeders to take some decisions that might immediately help to breed away from severer forms, so a lot have been disappointed that this small initial study didn't show a connection.

24th May 2007, 08:46 PM
Unfortunately, the most obvious reason is rarely the answer.

24th May 2007, 08:48 PM
Unfortunately, the most obvious reason is rarely the answer.

and so frustrating that it's not. :confused:

24th May 2007, 08:55 PM
Well, there is a certain element of direct connection -- researchers have only seen this type of SM in brachycephalic (short nosed) dogs so it does seem in some way connected to changes to dog head shape. One Swedish study connects it as well to dogs with a steeper occiput (back of skull). But not apparently in the more obvious way people had hoped. Nonetheless one of the key researchers on the DNA project thinks there may be some connection to changes inhead shape in the 80s when certain sires also became very popular and the gene pool narrowed.

More research and scans needed, as always!

24th May 2007, 09:08 PM
We have to be so careful that this connection with the 80's isn't a red herring. I suspect it is.