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View Full Version : Significant new Chiari-like malformation findings



RodRussell
14th April 2012, 06:57 PM
In an April 2012 report, UK researchers Thomas A. Shaw, Imelda M. McGonnell, Colin J. Driver, Clare Rusbridge, and Holger A. Volk, confirmed previous studies that cavalier King Charles spaniels have proportionately larger cerebellums than other small breeds and Labradors. They also found an association between the CKCS's oversized brains and SM.

Read the details at http://cavalierhealth.org/syringomyelia.htm#most_recent_findings

Karlin
15th April 2012, 10:52 PM
Thanks for that -- I hadn't seen this yet! It's a great mix of to researchers too -- nice to see Clare Rusbridge and Imelda McGonnell (who is doing the foetal tissue work that has largely corroborated early speculation by other researchers) in collaboration. :)

waldor
16th April 2012, 03:02 PM
Very interesting reading. Forgive my ignorance, but why do they mention Labradors so often?

Karlin
16th April 2012, 03:14 PM
I believe because it is also a breed that can have an oversized cerebellum and makes a contrast comparison as it is a medium rather than small breed. Or it may be simply that early on research indicated that cavaliers have a cerebellum the size of a labrador's -- much larger than other small breed dogs in other words -- but still a small dog skull size. That made for Clare Rusbridge's comparison in Pedigree Dogs Exposed to the CKCS brain and skull being like squeezing a large foot into a small shoe. Which going by this paper bringing in and using Imelda McGonnell's foetal research, looks to be exactly right -- there's a mismatch between cerebellum size and skull size.

Alana
17th April 2012, 12:07 PM
"In a study conducted by Dr. Rusbridge and Ms. Knowler, in a sample of seventy "unaffected" cavaliers from Europe and North America, which were MRI-scanned only for breeding purposes, 70% of them had syringomyelia, 17% were "at risk", meaning were young dogs with Chiari-like malformation but no syringomyelia yet, and only 13% were "clear" of both the malformation and SM. In February 2010, Dr. Georgina Child, board certified veterinary neurologist in Australia, reported that of 60 asymptomatic cavaliers scanned as potential breeding stock, 50% had SM syrinxes."

Thank you for this research. Breeders in Australia ignore SM and believe it is a condition that affects UK and US Cavaliers and not Cavaliers in Australia...how stupid are these people? Where do they think their Breeding Cavaliers came from? Hello! The UK and US! I love the beginning of the paragraph too about "Unaffected" cavaliers.

JessieAndMe
17th April 2012, 12:35 PM
Forgive me, but is it as simple as Cavaliers with larger frames, and therefore, larger skulls are not as high a risk to develop syringomyelia? I've read that most statistics state at what age syringomyelia is found to be present, symptoms and sadly, the diagnosis, but haven't been able to find any studies on breed sizes and the rate of syringomyelia being present.

Or is research still too early to know more details as yet?

Kate H
17th April 2012, 12:39 PM
And a research project in America, which examined 'asymptomatic' Cavaliers with SM, found that something like 70% of them actually had symptoms that simply weren't being picked up as symptoms of SM, just treated as allergies, restlessness, squinting a bit in sunlight, or cute Cavalier characteristics like head rubbing. The list of symptoms that could betray SM is actually vast and vets as well as owners simply don't put two and two together until the pain really kicks in. Personally, I'm not sure that 'asymptomatic SM' actually exists - just wilfully blind or understandably ignorant owners, and vets inexperienced with SM.

Kate, Oliver and Aled

PS And picking up JesssieandMe's query, the researchers seem to agree that actual skull size makes no difference, because the cause is a mismatch between bone growth and brain growth - the skull stops growing but the brain doesn't get the message and carries on growing. So it doesn't matter if the skull grows big before it stops, the brain still doesn't get the stop message. Something similar happens with many cancers: the gene responsible for cell growth mutates/changes so that it becomes deaf to orders to stop its activity, and just goes on producing cells in places it shouldn't.