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View Full Version : Can SM Rear it's Ugly Head at Any Age



jankal
30th June 2009, 05:46 PM
I have two cavaliers, Lucy is 9 months, and Tanner is 7 months. I read that SM symptoms start appearing at about 6 months. Can it show up later?

WoodHaven
30th June 2009, 06:01 PM
Yes, at any age. This is why MRI's taken when a dog is older have much more "meaning" than ones taken at 6 months.

Kimmisue
30th June 2009, 06:01 PM
I don't know about later but my Reggie showed symptoms 2 weeks after I got him at 5 months old.

harleyfarley
30th June 2009, 06:10 PM
yes but i think the chari malformation and show up once the dog is fully grown, like harley has he is 3, without a malformation you cant get sm. di

WoodHaven
30th June 2009, 06:16 PM
yes but i think the chari malformation and show up once the dog is fully grown, like harley has he is 3, without a malformation you cant get sm. di

That isn't exactly true. From the Mayo Clinic:
Syringomyelia has several possible causes. The majority of syringomyelia cases are associated with Chiari malformation, a condition in which brain tissue protrudes into your spinal canal. Other causes of syringomyelia include spinal cord tumors, spinal cord injuries and damage caused by inflammation around your spinal cord.

harleyfarley
30th June 2009, 06:26 PM
I was thinking hereditary, as in puppys, not sure when the malforation would be visable on a scan. di

jankal
30th June 2009, 06:26 PM
Does the size of the cavalier play a role in the possiblilty of them having SM? Lucy is a larger cav and Tanner is on the small side.

Karlin
30th June 2009, 06:26 PM
You can definitely get SM without the malformation. This was documented in the recent research on Brussels griffons with SM/CLM by Clare Rusbridge and is also seen in cavaliers but I don't think with the same frequency going on published studies.

The foetal tissue CKCS research indicates changes in skull and brain development happen at a developmental stage while pups are still in utero. Neurologists have seen puppies 8-12 weeks with SM and elderly dogs suddenly showing symptoms including severe symptoms. However it seems that most cases tend to show symptoms by age 4-5. Researchers used to say under 2-ish but have moved out the age of 'early onset' now as more dogs are diagnosed and they get a better overall picture.

Researchers/neurologists pretty much are in accord that symptoms under one year tend to be the worst and most severe cases.

Clare Rusbridge has lots of info on all this on her website in the SM FAQ. There's links pinned at the top of the SM/MVD forum.

harleyfarley
30th June 2009, 06:33 PM
Does the size of the cavalier play a role in the possiblilty of them having SM? Lucy is a larger cav and Tanner is on the small side.

I think it depends of where the gene of the dog originated from.

Ive read that a larger spaniel and a flat nosed type toy dog were used to create a new breed (cav king charles) if the gene that predeposes the brain is from the spaniel and the gene that predeposes the skull from the toy dog, then you have a brain that too big for the skull size or shape. This creates the chari-malformation. I dont know if some cavs, have genes from only the spaniels making them a larger cav, or the smaller toy dog making them a more petite cav, there is certainly a wide variety is sizes of cavs. Its certainly an interesting concept. di

jankal
30th June 2009, 06:39 PM
I think it depends of where the gene of the dog originated from.

Ive read that a larger spaniel and a flat nosed type toy dog were used to create a new breed (cav king charles) if the gene that predeposes the brain is from the spaniel and the gene that predeposes the skull from the toy dog, then you have a brain that too big for the skull size or shape. This creates the chari-malformation. I dont know if some cavs, have genes from only the spaniels making them a larger cav, or the smaller toy dog making them a more petite cav, there is certainly a wide variety is sizes of cavs. Its certainly an interesting concept. di

Thanks so much everyone. I have never fallen in love with a breed of dogs the way I have the Cavs. I do have health guarantees from the the breeders but, I must say I was ignorant about the health issues. It would just kill me to see them suffer in any way.

Karlin
30th June 2009, 10:31 PM
Nothing is known about what produces the Chiari-like malformation or SM. The predisposing factor seems to be being a toy breed and a flatter nosed toy breed. That's it. There are other toy breeds affected as well.

Size plays no role at all, as far as has been seen. Neurologists will say they see cavaliers of all sizes presenting with SM. A large or small head also does not make any difference: very subtle internal skull measurements do seem to play a role but 99.99% of people would not be able to look at the external skull and be aware of what that better shape would be and it isn't related to overall size at all. However I sure wouldn't be trying to buy extra small cavaliers because breeders who breed for especially tiny dogs are going well outside the breed standard and are going to be clueless about health to begin with. In addition there is evidence as noted that shrinking the size of a breed is a factor so I sure wouldn't be adding any potential additional risk.

Finally I meant to say seeing symptoms at 6 months would actually be unusual. That would be very early onset and probably the worst level of severity. Most dogs would seem to show symptoms more at age 1+ according to neurologists, with 2-5 being pretty common an age spread. Like MVD SM is a progressive condition so symptoms are far more likely to show later, not earlier.