View Full Version : Littermates with SM

30th April 2009, 02:50 PM
Does anyone know the incidence of SM appearing in more than one dog from a litter? Eg, if my dog is diagnosed with it, what is the likelihood of his siblings also having it?
Karlin, I haven't been able to open the links on the "Site resources for SM" thread, maybe its just my pc?

30th April 2009, 07:14 PM
I fixed the links; thanks! They were outdated.

Clare Rusbridge has found with the Dutch breeders' scanning programme that clear dogs tend to be related to clear dogs and affected to affected. As inheritance isn't fully understood it is impossible to give percentages at this time however.

The genome project should help make inheritance much clearer.

Love my Cavaliers
30th April 2009, 10:57 PM
Riley was almost 6 when she was diagnosed with SM. So far her half sister Madison (same dad) is still clear. I did notify the breeder as soon as I found out about Riley and she said she only knew of one other of her dogs having SM and that dog was much younger than Riley. But, that doesn't mean Riley's littermates are clear - just that nobody has talked to the breeder if their dog is affected. I think that's probably a problem you'll find especially if dogs are diagnosed at an older age. I just happen to have a good relationship with their breeder and wanted her to know.

1st May 2009, 11:56 AM
I think that's probably a problem you'll find especially if dogs are diagnosed at an older age.

Yes this is a big issue. I'd say the majority of people do not contact their breeders when given a diagnosis, for a wide range of reasons -- they didn't stay in contact, they don't have an easy way to reach them, they are fearful of telling them, they have seen the reaction some have had from breeders (which ranges from disinterest to threats to rudeness). Fortunately there are some great, supportive breeders too. :) The breed's real heroes are the breeders who consistently work to get as much information as they can about their own dogs and progeny and support their pet owners and breed carefully with more than just ribbons in mind.

The existing research shows a strong tendency for extended cavalier families to have affected or unaffected near relatives. The genome research also shows inheritance is a major factor, far outweighing other possible factors. Problem is it isn't yet understood.

in the US in particular, breeders are unlikely to know whether they are producing affected dogs unless they scan their dogs. Scanning still is costly there so neither breeders nor pet owners tend to scan unless they have a symptomatic dog or are really committed to research and getting info on their own lines. So while it may be that breeders believe they have produced few or no affected dogs, it is very hard for them to know what their dogs might be producing or whether they are themselves affected without scans having been done (and if more scans were done, more truly clear dogs would be identified, with greater hope for the breed as a result). I am quite sure my most affected dog, Leo, would have gone unnoticed til well into his breeding career had he remained (as was intended) part of the breeder's breeding programme. He had no symptoms for 2.5 years and many breeders would have begun using him at age 1 at stud (my breeder, now deceased, had asked to do so if I wasn't neutering him). He was a kennel dog and in with two dozen other dogs; I doubt his symptoms would have stood out until he was close to the age he is now (5.5). I imagine this scenario has been repeated many times in many places. And I know of cases where some breeders in the UK have sold on dogs they knew were affected to North America, where they continue to be used at stud.

These are amongst those arguing against scanning dogs.

I continue to be amazed that these people can live with themselves.

Margaret C
1st May 2009, 10:48 PM
I was really quite stunned when Matthew was scanned at the age of six & shown to have a syrinx.
He had no symptoms whatsoever, and moved beautifully.
I already had some knowledge of SM, so it was not because I missed any signs.

He is now nearly eleven and there are times when I suspect he may have some considerable discomfort.
Some days he keeps dropping into a prone position with his head outsretched between his paws, just like an affected puppy that was shown in one of Dr Rusbridge's videos. I think it is a way to relieve the pressure inside his head.

He will still come forward to be cuddled & and then shys away when I put out my hand to touch him..... Heartbreaking really in a cavalier.

He is such a stoic little dog. I doubt whether his behaviour would be noticed in a kennel situation.

Margaret C

2nd May 2009, 12:54 AM
Some days he keeps dropping into a prone position with his head outsretched between his paws, just like an affected puppy that was shown in one of Dr Rusbridge's videos. I think it is a way to relieve the pressure inside his head.

Dylan does this too and you describe it well by saying "dropping" into this position which is what I think what makes it different from a dog simply lying like this (just my opinion). Dylan plops quite heavy into this position.
..and a rather odd attempt to stretch his neck.

2nd May 2009, 02:25 AM
Awww, sweet Dylan.

3rd May 2009, 05:42 PM
I don't think lying like that means anything on its own, Pauline, as it is very common. Have you seen the video Margaret is describing? The pup drops quickly and suddenly into this position every time it starts to do some activity -- it is very different from just plopping down and going to sleep or resting, it is clearly a reaction to shooting pain of some sort. It doesn't then rest like a dog having a nap; instead it just holds the position for a little while, looking very uncomfortable, and then struggles to get up try and do something then drops again, in pain.

Simply lying like that or plopping into the position to rest -- that's pretty normal in my house -- all my dogs sleep like that including two that have excellent scans and will drop into the position of lying down. I don't want people to become overly concerned about what is most likely pretty normal dog behaviour. :thmbsup:

For anyone wondering about possible symptoms, there's an extensive list of potential symptoms that neurologists have confirmed, here (http://sm.cavaliertalk.com/diagnosing/diagnosing/symptoms.html).

3rd May 2009, 05:48 PM
I was gonna say, OMG Harley does this all the time, its his favourite laying positions and he usually heaves a big sigh too.


By the way this pick is before harley lost his weight, hes not quite so much of a dumpling any more.

Ruth M
4th May 2009, 10:09 AM
Tilly lies like Dylan most of the time too - I am sure that this is due to her discomfort. Most distressing is when she lies down and pushes her neck back against the wall/furniture - so far back that it looks like her neck is broken! :( This seems to give her some relief on a bad day.

Does anyone know how the RVC trials went and if the trialled drug will go on general release? icon_nwunsureThis has probably already been discussed but I couldn't find a thread.

4th May 2009, 08:47 PM
It will probably be a year or two before results are published from the trial, as far as I know. There's a long process to approving a drug for other use than whatever it was originally designated for. Havn't heard anything -- maybe someone will want to check with the RVC if they are there as a patient?

On lying in this position -- this is a very, very common position for dogs -- not just cavaliers but all breeds. I just came back from friends where a jack russell, two westies, and my clear dog Jaspar ALL were lying on the floor and dogbeds like this. None has SM. I know of many large breeds that lie like this as well.

Once again: I have seen the video Margeret is referencing. It has NOTHING to do with dogs resting in this position. It is of a dog that struggles to do something, clearly feels pain, drops to this position, tries to rise to do something again, drops to this position -- entirely different thing from a dog simply lying in this position, which is very NORMAL for all breeds of dog.