nieuws voor de cavalier

http://www.cavalierhealth.org/editorial.htm#June_21,_2011

De link doet het niet maar dit staat er dus

If the SM Breeding Protocol is Followed?

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Dr. Clare Rusbridge Thinks So

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Netherlands Cavaliers Show Startling Improvement
Dr. Clare Rusbridge writes in her blog today about a comparison study of 380 cavalier King Charles spaniels which suggests that faithful adherence to the Syringomyelia Breeding Protocol will reduce the incidence of SM in future generations. The chart (seen here at the right) from her blog compares MRIs of asymptomatic CKCSs during 2004 through 2006 with those of 2007 through 2009. For cavaliers in the Netherlands, it shows that the percentage of SM-affected dogs dropped from a whopping 82% in 2004-2006 to 48% -- less than half(!) -- during 2007-2009.

That is a startling improvement! But the latest news from Holland gets even better! Dr. Rusbridge adds, "The current % of no SM 'A' grades reported for the Netherlands in 2010-11 is estimated at about 70%." That means, of course, that the percentage of SM-affected cavaliers in Holland has dropped from 82% in 2004-2006 to only 30% in 2010-2011.

Meanwhile, in the other countries in the study (UK, Australia, USA, and Canada) there was virtually no change from the 68% in 2004-2006 to the 67% in 2007-2009.

Why the difference and so much improvement in Holland? Dr. Rusbridge suggests that there, the breeders had been following the SM breeding protocol since 2004. If this theory is correct, then every cavalier breeder should either follow that protocol to the letter, or not breed cavaliers anymore.

How the Syringomyelia Breeding Protocol
Could Lead to the Popular Sire Syndrome

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Many "D" Bitches Mated With the Same "A" Stud = Another Genetic Crisis for the CKCS
For corner-cutting breeders of cavalier King Charles spaniels, trying to follow the syringomyelia (SM) breeding protocol could lead to a uprising of the dreaded Popular Sire Syndrome.

The current SM breeding protocol, introduced to the cavalier King Charles spaniel community in 2006 by the International Syringomyelia Conference, only requires that one of a breeding pair of cavaliers not have syringomyelia. The other cavalier of that pair may either have syringomyelia but without any symptoms – according to its magnetic resonance imaging (MRI) scan – or it may not even have been MRI scanned at all.

Specifically, the protocol provides that a dog classified as an "A" must be over 2.5 years of age and that SM is "absent or less than 2mm central canal dilatation in the C2-C4 region only". A "D" cavalier is one which is over 2.5 years and diagnosed by MRI to have "asymptomatic" SM, meaning that the dog has the disease but does not act like it does. That is one way a cavalier may be classified as a "D". The other way is to be over 2.5 years but to not be MRI scanned at all. So, as long as the dog is over 2.5 years and does not behave like it is suffering from SM, it is a "D" dog. This is known as a "default D" dog.

Most cavalier breeders have more female breeding stock than males. Having too many – in some cases even just one – intact males around can cause more problems than the males are worth. So, most cavalier breeders who do not rely much upon line breeding, will hire other breeders’ studs for mating, rather than keep the dogs in their own households with all those bitches around.

When a financially-challenged CKCS breeder with, say, a half dozen bitches as her breeding stock, considers the SM breeding protocol, she finds that MRI scanning can be quite costly. One thorough scan for just one bitch can cost thousands of dollars, when the ancillary procedures are taken into account, such as blood tests, anesthesia, radiologist and neurologist fees, transportation, etc. Multiply that cost by the number of bitches in the breeder’s kennel, and then maybe double that figure, since more than one MRI scan could be necessary during the breeding years for each bitch. Dealing with just this one protocol for this one genetic disorder could wipe out any hopes of the breeder breaking even on the litters all of her bitches could be hoped to produce.

An apparent solution to this breeder’s dilemma is the option under the SM protocol to not scan her breeding stock at all. If they don’t have symptoms of SM, then she can call all of them "D"s, hence the term, "default D". And if she can find a sire which has been MRI scanned and classified an "A", she could use that sire on all of her "default D"s and still satisfy the SM protocol.

Super om te lezen. Dat is wat verantwoord fokken, met het testen van erfelijke aandoeningen en uitsluiten van niet-vrije honden dus met een ras kan doen. Geweldig.

Ja Angela helemaal Toppie toch

"a comparison study of 380 cavalier King Charles spaniels"

Het positieve bericht is helaas verwijderd.
De studie bevatte "slechts" 380 cavaliers, waardoor de cijfers wel eens verkeerd uitgelegd zouden kunnen worden....

De studie van Mrs.Rusbridge waarop zij destijds promoveerde in 2007 te Utrecht,
co-promotor P. Mandigers, bevatte 25 cavaliers en 60 scans.
Dat was genoeg om de hele wereldpopulatie vervolgens op af te rekenen en die percentages worden heden ten dage nog steeds gehanteerd......

Gezien de ontwikkelingen in Nederland kunnen we het item van 21 juni weer toevoegen aan the neverending story, de heksenjacht op de Cavalier, ontstaan door keer op keer de wereld ingeblazen verkeerd geinterpreteerde cijfers en percentages.

Altijd negatief, nu eindelijk eens positief en iedere fokker motiverend...
Helaas duurde het maar 1 dag.