PDA

View Full Version : Chiari-like malformation is found to be progressive



RodRussell
16th July 2011, 05:56 PM
UK researchers, including Drs. Rusbridge, Driver, and McGonnell, reported to the ACVIM in a June 2011 study that CM-affected cavaliers' foramen magnums and the length of cerebellar herniation "increased significantly" between MRI scans averaging 9.5 months apart. they concluded:

"This work could suggest that overcrowding of the caudal cranial fossa in conjunction with the movements of cerebrospinal fluid and cerebellar tissue secondary to pulse pressures created during the cardiac cycle causes pressures on the occipital bone. This leads to a resorption of the bone and therefore an increase in caudal cranial fossa and foramen magnum size allowing cerebellar herniation length to increase."

See http://bit.ly/qUJK1F for more details.

anniemac
16th July 2011, 06:07 PM
I thought I was going to have a day off but can you please explain in laymans terms? What about mild cm that never develops a syrinx but is symptomatic? Does this have some help with the friend we have?

Sent from my Droid using Tapatalk

anniemac
16th July 2011, 06:12 PM
If I'm reading it right that cm doesn't determine presence of sm and other factors? That's something I've wondered about. Do we know if they were symptomatic? I'm asking because so many people feel severity of SM but knowing symptomatic CM cavaliers like Dougal for example

Sent from my Droid using Tapatalk

RodRussell
16th July 2011, 06:24 PM
I thought I was going to have a day off but can you please explain in laymans terms? What about mild cm that never develops a syrinx but is symptomatic? Does this have some help with the friend we have?

I think it means that CM can get worse. The foramen magnum -- that hole in the back of the occipital bone of the skull -- actually can get bigger, and as it does, more of the cerebellum can squeeze through.

The researchers' hypothesis is that the over-sized cerebellum, combined with the movements of cerebrospinal fluid and cerebellum during heart beats, cause pressure on the occipital bone. This leads to the bone reducing in size, thereby enlarging the foramen magnum, allowing more of the cerebellum to squeeze through.

That is all I know.

Tania
16th July 2011, 06:35 PM
Thank you for explaining this. :(

Margaret C
17th July 2011, 12:26 AM
UK researchers, including Drs. Rusbridge, Driver, and McGonnell, reported to the ACVIM in a June 2011 study that CM-affected cavaliers' foramen magnums and the length of cerebellar herniation "increased significantly" between MRI scans averaging 9.5 months apart. they concluded:

"This work could suggest that overcrowding of the caudal cranial fossa in conjunction with the movements of cerebrospinal fluid and cerebellar tissue secondary to pulse pressures created during the cardiac cycle causes pressures on the occipital bone. This leads to a resorption of the bone and therefore an increase in caudal cranial fossa and foramen magnum size allowing cerebellar herniation length to increase."

See http://bit.ly/qUJK1F for more details.

At the health day last November Dr McGonnell reported that all the cavalier whelps she studied in the Foetal Tissue Research had a suture in the middle of the Supraoccipital bone ( apparently it is unusual to find this within bone ) which appeared to close before birth ( early fusion )

The whelps had less high quality ( weak ) bone, lots of marrow and increased blood cells and they all had disorganised structure and large blood vessels.

http://www.cavaliertalk.com/forums/entry.php?149-The-Cavalier-Club-Health-Day.-Part-4-Foetal-Tissue-Research

I wonder if this weak bone in the cavalier skull contributes to the reported resorption.

At post-mortem Monty ( Ch. Mareve Indiana ) was found to have a large keyhole shaped foramen magnum.
The hole was partly covered by cartilage and that was possibly the reason his symptoms did not manifest until he was an old man. The cartilage was more flexible and crushed his brain less than the bone that would normally be there.

Margaret C
18th July 2011, 01:15 AM
I see this announcement brought the usual reaction from breeders who demand they should be given up-to-date information, but then attacks anything that suggests there really are deep seated health problems in Cavaliers.

An abstract written by leading researchers, including the formerly highly praised head of the Foetal Tissue Research, gives proven facts about 12 cavaliers and suggests what may be happening.

Below is an illustration on how it was received.

In a couple of weeks time the highlighted words and phrases will be parroted by people that have not even read the report..................

Some people are very good at making the bullets for others to fire..........................

"A study conducted on 12 dogs ............ I have faith in the researchers, but find it difficult to accept on those figures that one could make any hard and fast statement, surely?"

"I just find it really difficult to swallow these sweeping statements based on such a small percentage of dogs"



"What I have a problem with it how can you reasonably expect anyone to take as "gospel" something based on 12 dogs.

Hard and fast statement? sweeping statements? gospel?

No, I don't think so. Just a report on a piece of research and a suggestion as to what it may mean.

anniemac
18th July 2011, 01:37 AM
Now wait a minute. I don't want to get in the middle of what people say but this topic does hit home. I'm not saying anything about this research because I know it is something we all want. I want to speak for 2 cavaliers and one specifically that is a pet owner just wanting answers. If you haven't read my blog, its funny because I just wrote about this before this came out. It has nothing to do with research. I can't speak for them because I don't know and I don't want to debate on a forum they are not on. You can read my blog www.fightforella.blogspot.com.

They have symptomatic CM cavaliers and bravely spoke out about it. I commend them for it and especially when they are scanning multiple times and helping with research. After the one with symptomatic CM she spent over a year researching getting a new cavalier from 2 fully scanned SM clear parents and even scanned grandparents.

Sent from my Droid using Tapatalk

RodRussell
18th July 2011, 02:00 AM
... They have symptomatic CM cavaliers and bravely spoke out about it. I commend them for it and especially when they are scanning multiple times and helping with research. After the one with symptomatic CM she spent over a year researching getting a new cavalier from 2 fully scanned CM/SM clear parents and even scanned grandparents.

I think symptomatic CM cavaliers (which means, the dog does not have SM, and therefore is an "A", but does suffer pain from CM) may be a loophole in the SM breeding protocol. The protocol okays breeding any cavalier which does not have SM. They are the "A" grade cavaliers. I long have suspected that the pain of CM/SM really is the pain of CM alone. I don't recall that any studies have refuted this hunch.

There are CM/SM cavaliers without symptoms, which includes no displays of pain. So it is possible to have SM and not, at least, give outward evidence of pain. And there are non-SM cavaliers, having only CM, which display signs of severe pain. So, why not reason that the pain experienced by CM/SM dogs is due to the CM and not the SM?

Should the SM breeding protocol be revised to ban symptomatic "A" cavaliers? I don't know, because it may be that breeding any "A" is better than breeding no "A" at all. This is a question for the geneticists and the neurologists to answer.

RodRussell
18th July 2011, 02:02 AM
I see this announcement brought the usual reaction from breeders who demand they should be given up-to-date information, but then attacks anything that suggests there really are deep seated health problems in Cavaliers. ...

Yes, interesting, isn't it? Thank you for being so concise in your analysis. I could not put my finger on the irony, like you have.

anniemac
18th July 2011, 02:12 AM
I think symptomatic CM cavaliers (which means, the dog does not have SM, and therefore is an "A", but does suffer pain from CM) may be a loophole in the SM breeding protocol. The protocol okays breeding any cavalier which does not have SM. They are the "A" grade cavaliers. I long have suspected that the pain of CM/SM really is the pain of CM alone. I don't recall that any studies have refuted this hunch.

There are CM/SM cavaliers without symptoms, which includes no displays of pain. So it is possible to have SM and not, at least, give outward evidence of pain. And there are non-SM cavaliers, having only CM, which display signs of severe pain. So, why not reason that the pain experienced by CM/SM dogs is due to the CM and not the SM?

Should the SM breeding protocol be revised to ban symptomatic "A" cavaliers? I don't know, because it may be that breeding any "A" is better than breeding no "A" at all. This is a question for the geneticists and the neurologists to answer.

Well my friend said I need to cm/sm will be here next week and I need to play with elton. I know one is a breeder but even with a very good "A" would never breed a symptomatic cavalier. I would think no one should breed any dog that is symptomatic of anything. Off to talk to my 10 lb rescue for a week, elton.

Sent from my Droid using Tapatalk

anniemac
18th July 2011, 02:26 AM
Just my 2 cents, sometimes I think its the cm and not sm too.

Sent from my Droid using Tapatalk

anniemac
18th July 2011, 02:29 AM
Rod,

I just edited my post but you quoted it. I stand corrected, the parents were SM clear but both grandparents were scanned. Bottom line, she did her research as will I if I ever get a puppy.

Sent from my Droid using Tapatalk

lovecavaliers
18th July 2011, 04:58 AM
This is very interesting given my Jack has moderate symptoms and CM with a subjective "pre-syrinx". It is so strange how some dogs with a large clearly visible syrinx are asymptomatic or have less symptoms than Jack who has mild to moderate CM with ?pre-syrinx. I wonder if I get Jack re-scanned if it will show an increase in his CM or possible true syrinx formation. Gosh I hate this disease!

Reptigirl
18th July 2011, 05:30 AM
Just my 2 cents, sometimes I think its the cm and not sm too.

Sent from my Droid using Tapatalk

I second that! Just from personal experience. I'm sure many of you saw the terrible videos of Flash as a puppy. He did not have SM but had moderate/sever CM. Although I fully expect he will have SM by the time we rescan him I saw just how painful the CM was for him.

Bet
18th July 2011, 11:23 AM
I second that! Just from personal experience. I'm sure many of you saw the terrible videos of Flash as a puppy. He did not have SM but had moderate/sever CM. Although I fully expect he will have SM by the time we rescan him I saw just how painful the CM was for him.


CHIARI-LIKE MALFORMATION IS FOUND TO BE PROGRESSIVE


Is it not the Genes that are causing the CM/SM Problems for our Cavaliers.

As has been said by the Researchers that there are Several/Many Genes involved in this Complex Problem for the Cavalier Breed.

As the Recent Veterinary Paper just Published has Reported ,Selective Cavalier Breeding for SM stated that the High Prevelance of SM suggests that Eliminating the Genetic Risk Factors may be difficult because the Prevelance of the Determinant Genes, those Genes which are causing CM/SM within the Cavalier Population is therefore likely to be High.

If the CM/SM Cavalier Problem is going to be difficult to over -come with Selective Breeding, this is very serious Information for the Cavalier Breed to have been given, in-fact for our Cavaliers ,I think it's the worst news possible they could get.

Bet

Karlin
18th July 2011, 03:28 PM
including the formerly highly praised head of the Foetal Tissue Research

I have always said to so many people, breeders and pet owners alike, that this researcher who had become flavour of the month with breeders as long as her research seemed safe and results distant and no real intractable problem was yet implied with the breed even at foetal stage, would suddenly be (like all the others) criticised and her results disputed as soon as she had actual results that showed otherwise.

So sad, so typical, but no surprise at all as it fits the pattern. Expect a cutoff now in support for her work and in donations, going on other experience.

So far even 800 dogs has been 'too small a sample' for research results for some. :rolleyes:

And if more whelp donations were made, there would be more information to work from.

I feel sorry for the breeders who have really championed this needed research and wonder if they have had a bit of an eye opening to the frustration felt by so many -- breeders and breed lovers -- at the general reception of research results by breed clubs. Though it does provide yet more evidence for the KC that there is a serious problem in the club breeder community, not just the dogs.

Surely all these *consistent* results that suggest *major*, widespread and deep-seated health problems in the breed cannot all be fluke results? :sl*p:

Karlin
18th July 2011, 03:39 PM
Just my 2 cents, sometimes I think its the cm and not sm too.

Not sure what you are saying, but the two are very clearly seen to be connected. However in dogs CM alone only rarely seems to cause problems and there's little evidence that CM is the source of the pain and not the SM that develops from it. It is known that some dogs like some humans have very different CSF movement and this almost surely accounts for why some dogs have more difficulty with CM alone. There are likely a lot of internal factors on how that fluid is moving and why it is more aggravating to one dog than the vast majority of dogs with SM.

I have only come across a tiny handful of dogs with CM causing significant symptoms and that is what the neurologists say as well. It rarely shows up as the sole factor on MRI. In such cases it is just as serious as SM and should not be discounted -- as it too often is -- as 'only' CM (as in 'thank God my dog 'only' has CM' -- if there are symptoms, it makes little difference to the dog).

As for why some dogs with lots of syrinxes have few to no symptoms -- this isn't a very common situation according to neurologists, so it isn;t 'the CM and not the SM', but it does happen. The reason why is likely to be the same as the above -- dogs vary in how the CSF moves; the size and shape of the syrinx will have an affect (eg a very long narrow set of syrinxes filling the spine is not 'worse' than a very short single wide and lopsided syrinx in terms of pain research, though it may look as if the MRI is 'worse'. It actually probably is not). And as Dr Marino has said many times in presentations -- syrinxes typically come on slowly, and dogs can adjust to the very slow progression to survive with the pain over time (a terrible situation though the body does sometimes adapt -- it isn't an excuse for not thinking there aren't serious issues in cavaliers having syrinxes in the first place no matter the symptoms or lack of same...). He has said he has seen MRIs in cavaliers where the dog has adapted to manage the pain, that if he'd seen in a dog that had just come in with trauma-induced SM -- eg as a result of a head impact or other accident -- the dog would almost definitely need to be euthenised as the pain would be unbearable.

Anyone who lives with any kind of pain syndrome will know that you do generally adjust over time to increased increments of pain. If the pain is mostly in the head, as is probably the case with canine SM (it is in humans), it may be very hard to ever see 'pain' that owners would recognise -- it may be that lots of those supposedly 'asymptomatic' dogs are not asymptomatic at all but suffer a good deal. There is a research programme that has just started to try and find ways to assess pain in SM dogs as the existing techniques only can pick up very obvious physical signs and few of the 'internal' signs that are most often reported by humans.

Rod, I don't think there is any implied gap in the breeding recommendations -- the neurologists who drew it up (and I was at the meeting where they approved it) definitely never thought any breeder would be so stupid or cruel as to breed a dog that is symptomatic for anything. You are right that perhaps on some reported evidence, the advice needs to now clearly state that A dogs show no symptoms, as is noted for lower grade dogs (D etc).

tuppenlil
18th July 2011, 05:15 PM
I had several conversations with breeders who were worried that their dogs were exhibiting some symptoms, but when they were subsequently scanned they were graded "A".

These breeders seemed to expect the scanning centre to confirm or deny their dog had symptoms. All the scanning centres can do is MRI scan and interpret the scan results.

Gives a "carte blanche" to breeders to disregard possible symptoms.

Unfortunately, the presence of symptoms of discomfort or pain is entirely down to breeder perception, understanding and HONESTY.

How many people see that which they do not want to see ?

Maggie

Margaret C
18th July 2011, 08:58 PM
I had several conversations with breeders who were worried that their dogs were exhibiting some symptoms, but when they were subsequently scanned they were graded "A".

These breeders seemed to expect the scanning centre to confirm or deny their dog had symptoms. All the scanning centres can do is MRI scan and interpret the scan results.

Gives a "carte blanche" to breeders to disregard possible symptoms.

Unfortunately, the presence of symptoms of discomfort or pain is entirely down to breeder perception, understanding and HONESTY.

How many people see that which they do not want to see ?

Maggie


According to one breeder who has read the above none of her wide circle of friends would breed from a cavalier that was anything other but normal in every way, however nice they were.

I understood her circle of breeder friends include those that used the BIS dog that was diagnosed with SM at the age of 14 months?
A dog widely known to be affected because the owner had shown the scan & certificate round championship shows.
A dog that scanned so badly that the neurologist said he should never be bred from, would not be described by most people as normal in every way.

anniemac
18th July 2011, 10:34 PM
I clearly don’t know enough to make a statement that the pain is from the CM not the SM, that is an oversimplified statement. All I know is on this forum, Flash, Jack, Dougall, and a couple of Cavaliers not on the forum have symptomatic CM. It’s a terrible thing and I’m so glad Karlin said;

“In such cases it is just as serious as SM and should not be discounted -- as it too often is -- as 'only' CM (as in 'thank God my dog 'only' has CM' -- if there are symptoms, it makes little difference to the dog).”

As to the fact why there are CM/SM asymptomatic and just CM symptomatic is a question that hopefully breeders, pet owners and others will work with researchers to maybe find clues. However few they are when you see videos of Flash in pain or others showing symptoms that look just as severe as SM, I feel for the owners wanting to know also.

As far as “A” symptomatic cavaliers being breed. If you saw the video of Flash, you can see that clearly he has symptoms. That is why personally, I would want to see the parents or go to shows to get to know the Cavaliers. Also, I believe breeders go to shows to evaluate the others.

Anyway, what is a “pre-syrinx”?

Kate H
18th July 2011, 10:36 PM
Tuppenlil wrote about breeders whose 'dogs were exhibiting some symptoms, but when they were subsequently scanned they were graded "A".'

What many breeders don't seem to realise is that CM alone can produce symptoms, so it is quite possible to have no syrinx but still show discomfort, due to the slowing down of the CSF and resultant dilation of the ventricles. The best we can do at the moment is breed away from SM, but actually the basic problem - which is much harder to tackle because it is so widespread in Cavaliers - is CM.

Kate, Oliverand Aled

Karen and Ruby
18th July 2011, 10:59 PM
Its hard to understand, when you live with a dog with pain associated with CM why any one would breed a dog to live with that!

Charlie started showing pain symptoms at 10 months old with his first screaming fit at 13 months! He claws at his face and scratches far far more than Ruby does (who is a moderate SM girl)!
He has massively dialated ventricles too ...


But you have to look at the bigger picture, there isn't any choice in the matter- as many have said, 90% of Cavaliers are affected with CM. With such a complicated make up of genes and inheritance it would be impossible to only breed dogs completely free of both! Are there any? To do that would mean crushing the gene pool and opening the doors to who knows what other health problems!

Karlin
18th July 2011, 11:09 PM
Yes, Kate, that summarises the situation pretty well I think (and Karen, we posted around the same time!). I think many of the breeders who post to various forums also know perfectly well that CM alone is a potential problem with the same symptoms -- if not, they really are selective in what they read and how they interpret. If any of these people would even consider breeding a symptomatic cavalier on the basis that it doesn't have syrinxes, that would be a pretty shocking condemnation of a breeding programme. If they claim the breeding guidelines currently suggest they should, then you really have to wonder about their common sense. I will nonethless pass along to Clare Rusbridge that there are people who might think it would be OK to breed a dog with no syrinxes and symptoms... :sl*p: as a small change of wording would make that clear in the breeding recommendations.

Anne, the problem of simply judging dogs at shows and in the show ring is it actually tells you nothing. Any breeder showing a dog they know would normally have symptoms is going to be medicating the dog so it doesn't scratch in the ring if at all possible. Talk to breeders privately and most will say they know of some dogs being shown that are affected and are clearly on gabapentin or similar. Many will also know of a well known dog given its championship despite showing obvious SM symptoms even when being shown, simply to allow the breeder to get their championship for sentimental reasons. Most -- I think even the most cynical -- were pretty shocked at that but it happened and the show circles are well aware that it happened. Hence for many reasons, I would never trust what I see on show demonstrates any reality regarding CM/SM. I would only trust careful research, openness on the breeder's side, and checking those health certs. That said meeting a breeder in person at a show is always a nice way to have a chat either at the starting point of research or to meet when you know that this is the breeder you want to work with. But I'd sure never gauge that decision on what the breeder is showing and whether their dogs show symptoms or not. On medication, Leo as well as many affected dogs here I am sure, could be shown with no symptoms.

I think the dogs are fortunate that canine CM does not seem as problematical on its own as human Chiari malformation. Most humans with symptoms have Chiari and some also go on to develop SM. Perhaps because of the way dogs are built, CM alone does not show up much as the sole cause of problems. By the time dogs are showing symptoms, it is almost always SM in the vast majority of cases (I would guess at least close to 95%). I also think many neurologists still miss small syrinxes and a dog with supposed CM alone probably also has the start of SM. And for many of these dogs, PSOM is probably also contributing to or may be the source of the symptoms being attributed to CM (or SM). It is a very complicated situation.

A pre-syrinx is something a bit more suspicious that a central canal dilation that hasn't actually formed a proper syrinx yet but is headed that way.

anniemac
18th July 2011, 11:33 PM
Karlin,

I wouldn't base things on one or the other. I would want to get to know the breeder, talk about health, go over tests etc. It's a big decision and right now I am having to decide about this rescue

Davecav
19th July 2011, 01:12 AM
I think all this is very interesting and a bit :confused: way above my head. Humans have CM and they suffer very badly from this from what I have read and gathered.
So these are the people who have bad symptoms and have been diagnosed. But there may be many others who don't have any symptoms but still have CM - I might have CM, you might have CM? but because we don't have a problem, then no one will know. not even us, yet we have children who might get the full blown disease.

I'm not sure what I'm trying to say here, but there are probaly lots of dogs that aren't suffering - who have the genetic makeup of this and look bad on a scan, and others when MRI scanned who look on screen exactly the same, but have loads of pain.:(

There looks as if there is much much more to all this, so how does a new pet owner or even a dedicted breeder go about it all now? given as read that a good breeder won't breed from a dog that shows signs of pain.:confused:

Bet
19th July 2011, 11:01 AM
I think all this is very interesting and a bit :confused: way above my head. Humans have CM and they suffer very badly from this from what I have read and gathered.
So these are the people who have bad symptoms and have been diagnosed. But there may be many others who don't have any symptoms but still have CM - I might have CM, you might have CM? but because we don't have a problem, then no one will know. not even us, yet we have children who might get the full blown disease.

I'm not sure what I'm trying to say here, but there are probaly lots of dogs that aren't suffering - who have the genetic makeup of this and look bad on a scan, and others when MRI scanned who look on screen exactly the same, but have loads of pain.:(

There looks as if there is much much more to all this, so how does a new pet owner or even a dedicted breeder go about it all now? given as read that a good breeder won't breed from a dog that shows signs of pain.:confused:


CHIARI-LIKE MALFORMATION IS FOUND TO BE PROGRESSIVE.

This is why the Latest Veterinary Paper Just Published ,Peer Reviewed, has said that Selective Cavalier Breeding for SM will be difficult to Eliminate the Genetic Risk Factors for SM ,because the Heritability of CM/SM has been shown to be COMPLEX ,with Several or Many Genes, there is NO DNA Tests on the Market for Complex Conditons, nor likely to be for years to come.

I think it is time for us who truly love the Cavalier Breed to Plead with the Researchers and Geneticists as to what can now be being done to stop Cavaliers from becoming extinct..

It cannot be left in the Hands of Cavalier Breeders ,they just don't have the Knowledge or Expertise about the Genetic Complexity of the CM/SM Problem

We have got to accept this ,and Hope that the Researchers and Geneticists will come to the Aid of our Beloved Cavaliers.

Bet

Margaret C
19th July 2011, 06:16 PM
I think all this is very interesting and a bit :confused: way above my head. Humans have CM and they suffer very badly from this from what I have read and gathered.
So these are the people who have bad symptoms and have been diagnosed. But there may be many others who don't have any symptoms but still have CM - I might have CM, you might have CM? but because we don't have a problem, then no one will know. not even us, yet we have children who might get the full blown disease.

I'm not sure what I'm trying to say here, but there are probaly lots of dogs that aren't suffering - who have the genetic makeup of this and look bad on a scan, and others when MRI scanned who look on screen exactly the same, but have loads of pain.:(

You are probably right, but they will all have the CM genes to pass on to their offspring, which is a grim thought.

A human CM sufferer would be unlucky to meet and marry another human CM sufferer, but with 98% of cavaliers with CM nearly every cavalier litter will be the product of two CM affected dogs, so doubling up on these genes with each cavalier generation.


There looks as if there is much much more to all this, so how does a new pet owner or even a dedicted breeder go about it all now? given as read that a good breeder won't breed from a dog that shows signs of pain.:confused:

Good breeders won't, if they have educated themselves enough to know what constitutes signs of pain.

But as Maggie has written.......
" the presence of symptoms of discomfort or pain is entirely down to breeder perception, understanding and HONESTY.

How many people see that which they do not want to see ?"

Pet owners and breeders alike sometimes find it hard to admit to themselves the truth that is staring them in the face.

Pet owners need to face the fact that this is a health compromised breed and if they are going to take the risk of owning a cavalier, for their own sake and the breed's sake they should support responsible breeders.

Dedicated breeders would obviously be breeding to the MVD & SM guidelines.
It would be selfish uncaring breeders that do not bother.