21st November 2008:

FINALLY - the MRI results have come through and, as expected, they are a mixture of good and bad news. First, some info:

Under the current scoring system set up by Clare Rusbridge BVMS DipECVN MRCVS (the specialist in veterinary neurology who first identified syringomyelia in 1997), Cavaliers are 'graded' from their MRI scans as follows:

The table is reproduced from The Cavalier Club website, where you can find much more information about all aspects of the breed.

You will notice that there is no grade 'B' - this and a previous 'A*' grading were removed due to the difficulty of accurate interpretation.

You will also notice that the breeding recommendations currently suggest that dogs over the age of 2½ that have syringomyelia but have no symptoms, ie, grade D, can be bred from, provided that their mate is a grade A. This is because it is suspected that syringomyelia is so widespread in the Cavalier population that to select only grade 'A's to breed from would deplete the available gene pool drastically, increasingly the possibility of some other, new, nasty condition to turn up in the breed. The age limit of 2½ is a bit arbitrary, but was picked because almost all dogs who will develop the condition will do so before the age of 3.

Further, you will see that grade 'C' dogs, ie, those with no syringomyelia (yet!) but who are under this age can be bred to grade 'A' dogs - and you might well think, why breed from them at all? Why not wait until they are at least 2½ and have a second grading before mating them? The reason such dogs are included as possible parents is because a bitch that doesn't have her first litter before the age of 3 is more likely to have birth complications; up to 20% of all whelpings go wrong anyway, sadly, and allowing a bitch to get too old before she is mated the first time increases the possibility of difficulties. For stud dogs, it seems a bit daft, but a dog who has never successfully mated in early life (once physically mature, of course) often doesn't seem to be able to learn how, no matter how enthusiastic he is at having a go!

It is also important that you understand that the genetic links of syringomyelia are not yet understood. Breeding together two 'A' graded dogs does not guarantee that you get 'A' graded puppies; we can only hope that we are increasing the chances of it. A dog with syringomyelia that has one 'A' grade parent and one 'D' or lower grade parent did not necessarily inherit the SM from the lower graded parent. If you or anybody you know is considering buying a Cavalier puppy, ask to see the certificates from both parents, as well as certificates to show that they are both free of MVD (heart disease) and eye problems, but understand that this does not mean that you are guaranteed a puppy that will never develop any of these problems. At present MVD is the greater risk when buying a Cavalier, and a breeder who does not check their stocks' hearts annually should be avoided.

So: to my own family of Cav's; here are the results:

- of the breeding bitches, Charlotte and Mabel are both graded 'A', Florence, sadly, is graded 'D'. Florence has had two litters, and I am writing to all her puppy owners individually. Florence will not be bred from again. I deeply regret that I bred from her without knowing her MRI status.

- of the young stock, Ysobel, Nimrod and Erica are all graded 'C'. At present I have no plans to breed from any of them, although this might change. I expect to have them re-scanned when they are older. Freddie has been given a grade 'E'. She will be neutered, and may be re-homed if she remains asymptomatic. Freddie is, of course, Florence's daughter. If she is re-homed, it will be only to someone who knows exactly what they are taking on, and in the best interests of Freddie - she will probably prefer to have undivided attention as someone's pet than kennelled with my 'gang'.

I am in the process of informing all relevant persons of this information, and will add my dogs' pedigrees and results to the database being built by the Animal Health Trust to further knowledge of this distressing condition, and its possible modes of inheritance.