Is it just pedigree dogs that suffer from SM?

[Princess Buttercup]

I was just wondering if it is common for cross-breed dogs to suffer from SM, or is it usually just pure breeds?

I have a 3yr old female KC/Shih-tzu cross (adopted her 3 months ago, so still getting used to what is "normal" for her), and she's doing a lot of things that make me paranoid she has SM. She will sometimes stop during a walk to scratch at her harness, and will scratch at her ears and face at home, and push her face along the rug. She scoots along on her bum a few times a week too (have had her anal glands emptied within the last few weeks), and lip-smacks quite a bit. I've never seen her fly catching or air scratching though. Just wondering if I'm being completely paranoid, or is it possible she could have it? I've mentioned it to our vet a couple of times, and she doesn't seem to think it likely at this stage. As we've only had her a few months, I'm really not sure if all of this is normal for her, or something I need to worry about...

[Karlin]

By KC do you mean King Charles or Cavalier King Charles -- they are two different breeds. Usually a KC means a King Charles. The Cavaliers on existing evidence have a far higher rate of SM than King Charles spaniels.

Regardless though both those breeds (King charles and Shih Tzu) have been known to have SM so it is indeed possible. However there are many reasons a dog could be doing what you are seeing and some of those behaviours are fairly normal for any dog. Your vet would want to eliminate lots of other possibilities first.

I have a checklist under the heading 'Is this SM?' (and also read the symptoms document) at www.smcavalier.com, both of which might be helpful.

I wouldn't worry unless you are seeing clearer signs of an actual problem -- eg discomfort and persistent scratching with no apparent cause.

[Karlin]

From Dr Clare Rusbridge's intro to SM:

INCIDENCE
The CKCS is overwhelmingly overrepresented for cases of CM/SM. There is no colour or sex predisposition. As shortened skull is a risk factor, any breed with a degree of brachycephalism and/or miniaturization could potentially be predisposed to CM/SM. To date the condition has been also reported in King Charles spaniels, Brussels griffons, Yorkshire terriers, Maltese terriers, Chihuahuas, Miniature dachshunds, Miniature/toy poodles, Bichon Frise, Pugs, Shih Tzus, Pomeranians, Staffordshire bull terriers, a Boston terrier, French bulldogs a Pekingese, a miniature Pinscher and a couple of cats. Recent studies suggest 35% of SM-affected dogs have clinical signs of the condition. The youngest reported dogs with SM have been 12 weeks old. Dogs may be presented at any age although the majority of dogs (approximately 45%) will develop first signs of the disease within the first year of life and approximately 40 % of cases have first signs between 1 and 4 years old. As many as 15% develop signs as mature dogs with the oldest reported case first developing signs of disease aged 6.8 years. Due to the vague nature of signs in some cases and lack of awareness about the disease there is often a considerable time period (mean 1.6 years) between the onset of signs and confirmation of a diagnosis.

http://sm.cavaliertalk.com/diagnosin...infosheet.html

[Princess Buttercup]

Thanks for the info, Karlin! I'll keep an eye on her - fingers crossed it's nothing.

She's a Cavalier cross - didn't realise there was a difference!