Page 15 of 17 FirstFirst ... 51314151617 LastLast
Results 141 to 150 of 170

Thread: A Cavalier film, health related, BBC1........

  1. #141
    Join Date
    Mar 2005
    Location
    Dublin, Ireland
    Posts
    23,882
    Post Thanks / Like
    Blog Entries
    15

    Default

    Bet, I am sorry you feel that way. But the element of uncertainty due to the occasional incorrect dog on a pedigree, especially from many, many years ago before better records were kept, would be statistically far too miniscule to make any real difference to the EBVs or the work that resulted in the MVD protocol or the role of inheritance in CM and SM. It is fairly easy these days to correct many inaccuracies too because so many people are aware of littermates and relations on pedigrees, especially for the key dogs that are most relevant to the genome work now.

    Sarah Blott also does not need further MRIs to prepare her EBVs -- as the newsletter noted earlier this year, she has actually completed EBVs for every single pedigreed cavalier alive right now in the UK. The job of making those ever more accurate will depend on adding more information via MRi, but primarily by adding the results of the Canadian genome project, which will link true genetic inheritance values to the breeding values for a given dog or line. Again, the occasional incorrect dog on past pedigrees is not going to alter those EBVs.

    Using cheek swabs, blood donations or whatever to link a dog and pedigree to a DNA profile is a standard that will likely come in for all dogs (I already own a dog that is DNA profiled by the breeder ). Already many good breeders do this s best practice, to guarantee that a given dog does have the parentage claimed on the pedigree. The IKC is talking about making this mandatory for all registered dogs. But this works both ways -- A DNA test can also verify that dogs could NOT be the ones noted on the pedigree. This is why it is also unlikely that a given dog and pedigree would be totally or significantly incorrect for research as the profile would be wrong for the dog.

    So there really is no issue of damaging Sarah's current funded work project even if no one submits another MRI right now, you can stop worrying about that. Also occasional inaccuracies on pedigrees will neiher have affected the accuracy of research work on MVD that led to the MVD protocol, nor to the initial genetic and DNA work that has already indicated -- as Sarah herself has noted -- that probably 70-80% of the likelihood a dog will develop SM is linked to inheritance. She will tell you this herself I am sure. However, the long term value of her EBVs once she has completed this work would depend on some people continuing to scan so that real scientific data from the scans can be added to the predictions of inheritance. There are good indications that many people will scan as many breeders have indicated an intention to obtain this data on their breeding dogs. Given the close relatedness between all cavaliers, much useful data will come from even small MRI samples.

    So your work before was not in vain in terms of the results. Sadly though it may well be seen to have been in vain if breeders do not actually use the MVD protocol that resulted! As the UK CKCS Club's own cardiologist Simon Swift has said several times -- including in Pedigree Dogs Exposed -- heart statistics within the UK club have not improved AT ALL in the years the club has recommended -- rather than required -- using the MVD protocol, and that this is due solely to breeders not following the protocol (stated in his open letter to the club that was posted the the UK CKCS club site for several weeks last year. in which he asked whether the club was truly serious about improving heart statistics in the breed and if so, was it not now time to REQUIRE cardiologist heart testing only, and the use of the protocol?).

    PS It is worth noting that all the pedigree information is what is in the records of the UK club, so if it were to be significantly incorrect, that would be a problem they would need to work to resolve. Nonetheless the inheritance values would not have been significantly affected over such a huge sample of pedigrees (15,000), tied to some 1500 MRIs I believe at this point, and many blood/cheek DNA samples that were donated as well.
    Karlin
    Cavaliers: Jaspar Leo Lily Tansy
    In memory: Lucy
    Cavalier SM Infosite:www.smcavaliers.com

  2. #142
    Join Date
    Feb 2007
    Location
    UK
    Posts
    1,592
    Post Thanks / Like
    Blog Entries
    15

    Default A Cavalier Film ,Health Related,BBC1

    Thats good that Cheek Swabs were taken for the Pedigrees for the Canadian Gene Research ,its so important that they are accurate .This makes the Scientific Information valuable

    Bet

  3. #143
    Join Date
    Aug 2005
    Posts
    52
    Post Thanks / Like

    Default EBV's

    Karlin
    Do you have any idea how long it will be before breeders can get help from Sarah?
    If they are trying to find the best match for their scanned girl?

    Evelyn

  4. #144
    Join Date
    Mar 2005
    Location
    Dublin, Ireland
    Posts
    23,882
    Post Thanks / Like
    Blog Entries
    15

    Default

    No idea -- this is what was said at the meeting:

    Estimated Breeding Values (EBVs)

    It was agreed that all scan results should be sent direct to Sarah Blott for her continuing research. It was noted that a consent form will be needed to allow results to be used for research, and this can be based on current forms used for hips and elbow examination. The format of the form will be agreed by the panel of neurologists and radiologists.

    It was noted that first estimates of breeding values are now available for every cavalier in the UK.

    There was discussion on when EBVs should be made available to breeders. It was suggested that should EBVs become available too soon, when the programme is still at a very early stage, results could be disappointing and may alienate breeders. It was agreed that more information (ie. further MVD and MRI results) should be obtained before the system is introduced, so that it is more reliable and thus more beneficial.

    It was noted that dogs do not have to be scanned to be given a breeding value. There are various ways in which EBVs could be presented to breeders. The AHT will work with the Breed Clubs over the coming months to determine the best way of doing this. The breeding value of each dog will change over the years, as information is obtained on its progeny.

    It was noted that Sarah Blott particularly requires information on clear dogs.

    This will be a web-based scheme but available in print from AHT, to any breeder on request.

    Sarah Blott agreed to produce a special leaflet for distribution to club members, explaining the scheme in layman’s terms.

    The AHT data collection will be used to provide breeders with EBVs for safer breeding programmes to reduce the incidence of both MVD and SM, and could include any other condition as appropriate in the future. The EBV system will become even more reliable when permanent identification (PI) is introduced throughout all members’ breeding stock.
    The full explanation from Sarah of her programme is here.

    This is exciting work:

    In addition to selecting away from individual known diseases, such as syringomyelia, it is important to consider the long-term health of the breed. Population diversity and maintenance of diversity is important in order to minimize the risk of future new diseases arising. We want to apply state-of-the-art genetic selection techniques that use optimal contribution theory to help avoid unequal representation of individuals in future generations or ‘genetic bottlenecks’ occurring. This ensures that increases in inbreeding and loss of diversity are minimized. Our aim is to develop internet-based tools that allow breeders to have direct access to these state-of-the-art techniques to help them make optimal selection decisions. The Cavalier King Charles Spaniel will be the first dog breed in the world for which these techniques will be available.
    One might guess that using the EBVs to promote diversity will also highlight the need to stop close linebreeding.

    Further background:

    Data collected by Penny Knowler and Clare Rusbridge is currently being used as the basis for the population-based analysis of heritability. Their database contains clinical observations for SM and CM on around 1,400 dogs and MRI scan results for around 700 of these dogs. We have also been given access to the full UK Kennel Club pedigree records for CKCS. This enables us to estimate the heritability of SM and the genetic correlations between SM and measurements made from the MRI scans. The information obtained from this analysis then allows us to derive estimated breeding values (EBVs) for all measured dogs as well as all dogs in the pedigree. Once the results of the gene mapping studies become available it is hoped to bring this information together with the population analysis to facilitate the calculation of genomic breeding values (geBVs). Early estimates of the heritability of SM suggest it is around 0.7-0.8* or that 70-80% of the variation between individuals is genetic in origin and about 20-30% is environmental. In the case of SM not much is known about the environmental influences and these may include in-utero or developmental effects. The heritability is sufficiently high, however, that genetic selection against the disease should be very successful. Heritabilities for Chiari Malformation, Cerebellar Herniation and Medullary Kinking are also very high. Genetic correlations between these traits and SM are positive and, interestingly, less than one. This suggests that different genes may be controlling SM and CM and that it will be possible to select against SM even if dogs have the malformation (CM).
    This is why supporting the Canadian genome study is crucial -- that is where the genomic info will come from:

    The accuracy of the EBV increases with numbers of offspring and this may take some time to achieve. In contrast, genomic breeding values (geBVs) provide a high accuracy from birth. By looking directly at the DNA genotypes we can see which genes were inherited from the sire and from the dam, without having to wait for offspring. Genomic breeding values can be used for accurate evaluation at an early stage, before the disease phenotype may be apparent and before a dog is used for breeding.
    Karlin
    Cavaliers: Jaspar Leo Lily Tansy
    In memory: Lucy
    Cavalier SM Infosite:www.smcavaliers.com

  5. #145
    Join Date
    Mar 2005
    Location
    Dublin, Ireland
    Posts
    23,882
    Post Thanks / Like
    Blog Entries
    15

    Default

    I'll post this to this thread as well:

    This article is on the UK Cavaliers website, and is very insightful on linebreeding and the problems it can cause in later generations as it quotes the woman widely credited with founding the modern CKCS, the woman who bred the dog on which the breed standard is based, Ann's Son, Mrs Pitt:

    as Mrs. A. Pitt the founder of the Cavalier Breed said in a Cavalier magazine here in Britain in 1957 no thought had been given as to the future health of the Cavaliers, because the breeders at that time were in-breeding over and over again to the same stud dogs. 1 do know that there were Cavaliers dying of heart trouble in the 1950's whether from M.V.D that will never be known, but quite a number of those Cavaliers were the result of in-bred pedigree backgrounds. Is this the reason why around 50% of the Cavaliers in Britain have heart murmurs by the age of 5 years of age? It's even worse in Canada where 50% have heart murmurs by 4 years age.


    Since those faulty genes could have come down through the generations because of close/line breeding I suppose those figures will be much the same in America because in breeding would have taken place to get the Cavalier breed established


    What this means is that for Britain 41 % of Cavaliers will be carriers of heart murmur genes and around 9% of Cavaliers will be clear of those faulty genes.

    [snip]

    Is this now the time for Cavalier breeders, for the future of the breed, to bite the bullet in order to widen the genetic pool of Cavaliers and start using Cavaliers for breeding that are not winning in the Show Ring?


    I have been collecting quite a few hundred pedigrees of Cavaliers who have died at a young age, 5-7 years from heart trouble, mainly from Cavalier Pet Owners, like ourselves over the years and very few Cavalier Breeders in Britain can say they've had no heart trouble in their lines
    One of many, many key articles written by Bet Hargreaves, who has campaigned for years for better heart health in the breed. She wrote this in 2000.

    http://www.cavaliers.co.uk/articles/...elonglived.htm
    Karlin
    Cavaliers: Jaspar Leo Lily Tansy
    In memory: Lucy
    Cavalier SM Infosite:www.smcavaliers.com

  6. #146
    Join Date
    Mar 2005
    Location
    Dublin, Ireland
    Posts
    23,882
    Post Thanks / Like
    Blog Entries
    15

    Default

    I am very concerned about a private email that is being widely crossposted by a health rep to a large CKCS club in the UK -- which publicly raises doubts about the professional capabilities of one of the most eminent neurologists in the UK, Mr Geoff Skerritt, and his abilities to produce and interpret an MRI. The email is written by a human rheumatologist in Australia (without veterinary background). It was Mr Skerritt who did the MRI on the Malvern stud dog. He has also done more MRIs for club breeders than any other single neurologist in the UK, at discount and often at club request, very deep discounts for special regional club screening days.

    I am sure some of you have seen this email. The doctor who wrote the email also claimed that people should not be overly concerned at high rates of the malformation in cavaliers because the Chairi 1 malformation in humans is actually 'common' anyway.

    Such a claim is extraordinary. So I tried to find out this doctor's background to be able to make such claims. He turns out to be an elderly, human rheumatologist in Australia, without any vet background, who hasn't published in his area in 30 years (going from what comes up on the publication indexes, a few papers in the late 60s and 70s).

    In contrast, Mr Skerritt is well recognised in the UK as a pioneer of veterinary imaging. He is author of the textbook 'Handbook of Veterinary MRI' and RCVS Fellow and Recognised Specialist in Veterinary Neurology, Diplomate of the European College of Veterinary Neurology; he is a former President of the ECVN and current Chairman of the RCVS Small Animal Surgery and Fellowship Boards.

    On the 'commoness' of Chiari 1 in humans: current research estimates likely human occurrence at 1:1200 (this figure is widely available from current published articles) -- or 0.08% of the human population, which is in medical circles definitely considered 'rare'. If only 1% of cavaliers have the malformation, then the cavalier rate is 12 times that of the human population. If it is, say, the 85% Geoff Skerritt has predicted, it is 1200 times the rate of human affectedness.

    Or put it another way -- the ACKCSC's own breed health survey in 2005 came back with an MRI-diagnosed level of SM of 4% at that time, which would of course be very low compared to all the study populations so far. Nonetheless, 4% is a level that Prof Larry Glickman, head of Purdue vet school, at that time termed worryingly high compared to the the normal dog population and caused him to mark the condition as an increasing breed concern.

    So, even if all the ongoing research is radically wrong and the level is actually down near the breed survey, the level would still be approaching 1 in 20 cavaliers, which to most people is not rare. That is an SM rate of 1:22, compared to the 'common' 1:1200 incidence of Chiari 1 malformation in humans. Which surely means the SM ratio, by comparison, is extremely common in cavaliers?

    I have suggested that it is a very serious matter indeed for all club breeders who have had dogs MRId if the health representative of a major UK CKCS club is allowing Mr Skerritt's professional bona fides to be openly challenged and that this surely requires some sort of adjudication, perhaps by a neutral panel of radiologists and neurologists which the club and KC themselves proposed be established recently to view MRIs. Alternatively Mr Skerritt should be allowed to offer and defend his reading of that MRI publicly?
    Karlin
    Cavaliers: Jaspar Leo Lily Tansy
    In memory: Lucy
    Cavalier SM Infosite:www.smcavaliers.com

  7. #147
    Join Date
    Oct 2006
    Location
    N.W.Iowa
    Posts
    1,324
    Post Thanks / Like

    Default

    Can't conceive of a rheumatologist commenting on a neurological field. Most specialists have a hard time keeping up within their own specialty let alone invading another which leads me to believe this might be a hoax but an ugly one if it does come under that category.Saw this specific email quoted on another site and did see some belief there-some people will believe anything they see written
    frecklesmom
    Learning new things everyday

  8. #148
    Join Date
    Mar 2005
    Location
    Dublin, Ireland
    Posts
    23,882
    Post Thanks / Like
    Blog Entries
    15

    Default

    Note the email does not dispute Geoff Skerritt's findings. It only disputes Geoff Skerritt's professionalism by alleging a poor quality MRI that he could not read himself. So the email actually proves nothing about the content of the MRI or dog in question.

    It is worth noting that vet MRIs are read differently, from different angles, than human MRIs.
    Karlin
    Cavaliers: Jaspar Leo Lily Tansy
    In memory: Lucy
    Cavalier SM Infosite:www.smcavaliers.com

  9. #149
    Join Date
    Mar 2005
    Location
    Dublin, Ireland
    Posts
    23,882
    Post Thanks / Like
    Blog Entries
    15

    Default

    I also see that the doctor's wife is a breeder of cavaliers in Australia.
    Karlin
    Cavaliers: Jaspar Leo Lily Tansy
    In memory: Lucy
    Cavalier SM Infosite:www.smcavaliers.com

  10. #150
    Join Date
    Oct 2006
    Location
    N.W.Iowa
    Posts
    1,324
    Post Thanks / Like

    Default

    For crying outloud, the plot thickens. Good hunting, Karlin !
    frecklesmom
    Learning new things everyday

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •