Reading the breed notes in the Our Dogs paper, I noticed that the two main Chihuahua breed clubs are organising a health seminar at which Dr Holgar Volk from the Royal Veterinary College is going to speak on epilepsy and - syringomyelia. I find it interesting that they feel there are enough breeders and show people interested (if not yet directly concerned) in SM in Chihuahuas to warrant putting on a seminar. I believe that hydrocephalous (fluid in the brain) is fairly common in Chihuahuas, and as the symptoms of this are very similar to the symptoms of dilated ventricles in Cavaliers, it may be that CM and/or CM/SM occurs more often in the breed than breeders realise.
Kate, Oliver and Aled
Would I be jumping to conclusions I wonder in speculating about a connection between epilepsy and SM? Or is it just co-incidence that both conditions are being covered by the same speaker? From what I've overheard the Chihuahua people saying at show lately there are quite a few cases of SM/CM showing up in their breed too. It's nice to know their breed club is showing some concern, but at the same time I'm sorry that their dogs have problems too.
It;s been pretty definitively established that there's no direct connection -- this has come up at the SM seminars and after. Jacques Penderis specialises in epilepsy as does Clare Rusbridge and both have said it is a separate but unfortunately regularly seen health problem in cavaliers. SM can sometimes cause seizures but that is different from epilepsy per se.
Epilepsy is more common in some breeds. Chihuahuas have a high degree of hydrocephalus and hydrocephalus is also a secondary cause of epilepsy so the two would be related in that breed.
Quite a few chihs have been MRId with SM -- it is excellent that breeders are being proactive and getting a speaker in on this. Other less affected breeds will have a much better opportunity of eliminating SM by tackling it openly as early as possible.