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In- Breeding and CKCS.

Bet said:
Could I just mention that there is a Survey taking place in Australia at the moment on the IN-Breeding Problem in Pedigree Dogs.

I contacted those involved in this Research explaining that the Cavaliers in Australia would probably have been exported from Britain in the early days ,and presumeably will have many of the same Genes and had had the In-Bred Back-grounds ........................

I have just received an E-Mail ,thanking me for this information , that it will be of interest .
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Bet you probably would have contacted Researchers in Australia. I think that the reply email you received might have included something like this:-
"The early indications of the research into the coefficient of inbreeding indicates that we have a low COI in Australia".

You may have read the following which I posted elswhere and I may as well post it here as some may be interested. In the following I noted this and I think that some time after that date I may post some more information on what may be happening in Australia.
"This form also sets a target for all clubs to develop a breeding practices policy by June 2010."

Also Dr Frank Nicholas mentioned below is actually an Emeritus Professor and apparently is doing some sort of heritable diseases database for the UK RSPCA, this where veterinarians around the UK can input information into the database, also I think that at Sydney University Associate Professor Paul McGreevy may also be involved with this. I think that the UK AHT and BVA just might also be involved, and remember a while back some comments were made after some UK Cavalier breeders arranged for question forms to be sent out to veterinarians so as to find out from them how many SM cases they may have seen in their practice. The APGAW and Bateson Reports both mention the importance of collecting health information and to have a database.

Anyway the following is from the DOC format document at this address.
http://www.dogsvictoria.org.au/assets/coi-research.doc

IMPORTANT NOTICE REGARDING
RESEARCH INTO COEFFICIENT OF INBREEDING IN PUREBRED DOGS.

In 2008, Dr Frank Nicholas, from Sydney University, approached the ANKC for approval to be granted access to the pedigree data from the ANKC national database. The reason for having access to this data was for research purposes in setting up a heritable diseases database. This was agreed at the ANKC conference held in October 2008.

It is important for all members to realise that the data supplied does not include any member’s personal details and is, in fact, totally non-identifying data that is given to anyone making pedigree enquiries into the database. The only difference is that the entire database was released rather than the normal practice of only releasing those details pertaining to a specific enquiry.

Part of the process of this research project is that two postgraduate students from the University of Sydney are using the data to conduct research into the coefficient of inbreeding (COI) of purebred dogs.

Considering the situation that arose in the United Kingdom as a result of a BBC television program concerning breeding practices amongst dog breeders in the UK, DOGS Victoria believes there is a possibility, that once the research students’ work is published, some public focus may arise in Australia about inbreeding of purebred dogs.

DOGS Victoria believes in being proactive and will be taking a leadership role on this issue. We are strongly recommending that all breeders, national breed councils, and breed clubs establish and implement an improved breeding practices policy with consideration for the overall health and welfare of your particular breed.

DOGS Victoria acknowledges that quite a number of national breed councils, breed clubs and breeders already have responsible breeding practices in place, and it is requested these breeding requirements, or litter registrations limitations (LRL), be forwarded to the DOGS Victoria office by emailing [email protected] .

If you, your club, or your national breed council requires assistance in developing a breeding practices policy, please feel free to contact DOGS Victoria by emailing [email protected] or the DOGS Victoria canine health committee by emailing [email protected] .

All clubs will have received a survey form from the DOGS Victoria office to assist in listing their breeding requirements or LRL. This form also sets a target for all clubs to develop a breeding practices policy by June 2010.

The early indications of the research into the coefficient of inbreeding indicates that we have a low COI in Australia, so the results of this research should show purebred dogs in a positive light in Australia, and as such we will continue to support this important research.
.
 
IN-BREEDING and CKCS

RodRussell said:
I think that some Cavalier breeders mate close relatives, not just for externally visible physical traits, but also for those less visible internal traits, particularly such as temperament and even genetic health (such as, an older sire with a healthy heart). So, I do not agree that the rule should be to never breed Cavaliers with ancestors in common within the most recent generations.


In-Breeding and CKCS


First of all could I just say thank you Karlin for understanding about my Problem ,for some reason my brain seems to go quicker than my mind some-times when I am Typing or Thinking.I will for sure after all this Carry-on watch out for this in Future Posts.

To the IN-BREEDING in our CKCS Breed.

Any -thing I have Posted has been from the information I have collected from Geneticists or other Experts and the Papers they have written about this Subject.

As an Example, in the recent Bateson Report ,Professor Sir P. Bateson said most emphatically that, Breeding Grand-Mother to Grand-Son, and Grand-Father to Grand -Daughter is NOT LINE BREEDING ,it is IN-BREEDING.

I am only quoting what he said.

I can only say ,that because of my interest in collecting Cavalier Pedigrees over many years, that seems to have been common Practice in our Cavalier Breed's Breeding Programs.

Whether that was right or wrong ,I am not qualified to say, but just have to take the word of Professor Sir P. Bateson about this.

Also I was told by Professor J Sampson from the Kennel Club ,a few years ago that ,IN-Breeding ,will not cause a Hereditary Problem in a Dog Breed ,it will just bring it to the Fore.

I am just stating a Fact here ,I collected Cavalier Pedigrees in the 1980's when Half- Brothers were being Mated to Half-Sisters, those Pedigrees were sent to Liverpool University, for their Research into Cavalier Health Problems, I do know that a Particular Gene was found that was giving the Researchers some interest and this Gene seemed to be be being involved with the Cavaliers' In-Breeding.

Bet
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Bet said:
RodRussell said:
... As an Example, in the recent Bateson Report ,Professor Sir P. Bateson said most emphatically that, Breeding Grand-Mother to Grand-Son, and Grand-Father to Grand -Daughter is NOT LINE BREEDING ,it is IN-BREEDING. ...
Click to expand...

I do not know anything about Prof. Bateson's qualifications to differentiate between line breeding and in-breeding, but if mating a grandmother to a grandson or a grandfather to a grandson is not line breeding, that what IS line breeding?
Click to expand...
 
In-BREEDING and CKCS

RodRussell said:
Bet said:
I do not know anything about Prof. Bateson's qualifications to differentiate between line breeding and in-breeding, but if mating a grandmother to a grandson or a grandfather to a grandson is not line breeding, that what IS line breeding?
Click to expand...

IN-BREEDING and CKCS



Professor Sir P.Bateson, is Emeritus Professor of Ethology at Cambridge University,Britain

He is President of the Zoological Society of London

Is a Research Scientist.

Has written many Books and Papers amongst them,. the Developmental Biology and also Genetics.

Was also asked by the Kennel Club to Chair an Independant Inquiry into Dog Breeding .

His Report was Published in January 2010.

All I know is that in Page 15 of his Report and also in Chapter 6,

If a Breeder Mates Grand- Father with Grand-Daughter ,Grand-Mother with Grand-Son , ,he or she is In-Breeding and doing so to a Marked Extent.

From Chapter 6 of the Report .Professor Sir P Bateson quotes Calboli et al ..2008.
About the Small Number of Animals that Founded a Breed.

In our Cavalier Breed ,there were 6 Founders .














Ann's Son

Wizbang Timothy, Ann's Son's Litter Brother

Carlo of Ttiweh

Duce of Braemore

Aristide of Ttweh

Kobba of Korunda

This was written by Mrs E. Booth in her Book , published 1983 ,from these 6 Stud Dogs the Breed was formed.

Some of these Dogs were also In-Bred them-selves.

Professor Sir P.Bateson also continues to explain that In-Breeding tends to Fix Recessive Deleterious Traits and thereby Increase the Number of Animals in which the Disease is apparent

Can any-body deny that the MVD Problem in Cavaliers is not apparent ,when it was said at the UK CKCS CLUB's AGM last years that 50% 0f Cavaliers will have a Heart Murmur at 5 years of age, and this is no better than it was 18 years ago.

Bet
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Bet said:
... Professor Sir P.Bateson also continues to explain that In-Breeding tends to Fix Recessive Deleterious Traits and thereby Increase the Number of Animals in which the Disease is apparent

Can any-body deny that the MVD Problem in Cavaliers is not apparent ,when it was said at the UK CKCS CLUB's AGM last years that 50% 0f Cavaliers will have a Heart Murmur at 5 years of age, and this is no better than it was 18 years ago. ...
Click to expand...

I don't doubt that in-breeding (or line-breeding, which is what we really are talking about) could fix recessive traits, but the assumption being made here is that in-breeding only makes a bloodline worse and cannot improve it.

For example, I would seriously consider mating a grandfather with a clear heart at, say 8 years, with his granddaughter with a clear heart at 2.5 years. That would be line-breeding, but what would be wrong with it?

You may answer by suggesting a "parade of horribles", such as hidden recessive genetic immune problems in the bloodline, which allegedly only line-breeding would bring to the fore. But, I don't agree. You don't have to line-breed to find out if your Cavaliers have immune problems or may be carriers of hip dysplasia, etc. You know that from your experiences with your breeding stock and their siblings. And if they have genetic immune problems or are HD carriers, then you also should take that knowledge into account when deciding whether to breed or not.
 
Rod, I don't believe there has been an assumption put out that inbreeding/linebreeding only makes lines worse, although I do believe there are some breeders that are defensive about this and that are possibly reading that assumption into every post on the topic. We all know that inbreeding/linebreeding has also been what has helped fix desirable traits.

Throughout the thread what has been mentioned is that "risks" are involved when using linebreeding/inbreeding, and that they have to be acknowledged instead of glossed over. I don't believe acknowledging those risks and how they have also negatively impacted dog breeds is a universal condemnation.

Prof. Bateson is well qualified and is very correct in bringing attention to this. These words of his, when speaking of disease, are spot on.

"In-Breeding tends to Fix Recessive Deleterious Traits and thereby Increase the Number of Animals in which the Disease is apparent"

(Geneticists, BTW, tend to call any mating of animals with known shared relatives inbreeding, and they don't differentiate between linebreeding and inbreeding as some breeders do in some species.)

You mention that for experienced breeders, knowledge of health of breeding stock and their ancestors are important indicators of what might crop up and should be taken into account. That is fantastic advice. It is, I believe, the backbone of good breeding whether a breeder is linebreeding or deliberately favoring the assortative breeding method (breeding like to like but not closely related).

Knowing background health is unfortunately not fool-proof especially in regards to conditions with polygenic modes of inheritance with any breeding method used. When linebreeding/inbreeding are used the risks DO increase. That is a lesson that should be learned when polygenic conditions that are normally incredibly rare in a population become widespread - like SM.

In an earlier post you mentioned that "line-breeding per se should not be universally condemned" and I happen to agree, but I believe there should be a much greater understanding of its impact on population genetics within the full breed, and greater cautions used around it than I have seen.

As a member of the Canine Genetics list for many years now I have read many breeders that avoid linebreeding to the extent that it has been mentored in many breeds through the last century. That does not mean that they universally condemn it. They still understand its use. They also offer suggestions of alternative breeding methods that already have proven themselves to fix desired traits but with less risk of doubling up recessives common ancestors.

As a former stock breeder I understand those.

This is one Welsh Corgi breeder that has made an excellent blog post on the topic speaking, from a dog breeders point of view, to all the considerations. I highly recommend reading through it as it covers the topic well.

Some excerpts:
"The breeders of production species have managed to create very high-quality breeding programs without using a high COI. . .

. . . That’s an important lesson, I think. They did it, and continue to do it, by pairing animals that move toward a desired look and a desired production level, without using close breedings.

I do want to be clear on this, now that I’ve made everybody mad: COI tells you nothing about whether the two dogs are going to produce high-quality offspring. I could get a really low COI by breeding to an entirely different breed, but that doesn’t mean it’s a good move. You still have to choose a stud dog or bitch based on his or her quality and health testing and so on. And a low COI shouldn’t trump the more immediate issues of temperament or disease. COI is one more tool you use to structure a breeding program, especially a long-term breeding program, and it helps you understand how your prospective matings will or will not support your efforts and what I hope are the efforts of your breed club.

Committing to a lower COI as much as you possibly can – not to the detriment of the dogs, but as a general rule – will create a breed that is substantially more sustainable over the long term (I mean decades or centuries here, which is–I hope–an important part of how breeders are planning their breedings)."
​
http://rufflyspeaking.wordpress.com...l-pairings-yet-more-on-pedigree-dogs-exposed/


And this is from Dr. Hellmuth Wachtell, and I believe, as well acknowledges that inbreeding/linebreeding has its uses, but also speaks to the current situation. It is NOT a condemnation of inbreeding, as some might read it, but a condemnation of the HABIT of inbreeding.
"Inbreeding was once a valuable tool in shaping today’s breeds. As these have now reached a high degree of homogeneity, it has lost its importance and turned into a fatal and disastrous habit."
​
http://www.canine-genetics.com/Price.htm

If dog breeds are to survive, the impact of individual's breeding programs, and how they relate to and impact on the population genetics situation within the full breed, have to be understood. COI is a tool that helps with that, and yes, lower COI litters (with members bred forward on) help to sustain genetic diversity in a closed gene pool breed, where as higher COI litters help to diminish it.

Oreo
 
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In-Breeding and CKCS

Oreo said:
Rod, I don't believe there has been an assumption put out that inbreeding/linebreeding only makes lines worse, although I do believe there are some breeders that are defensive about this and that are possibly reading that assumption into every post on the topic. We all know that inbreeding/linebreeding has also been what has helped fix desirable traits.

Throughout the thread what has been mentioned is that "risks" are involved when using linebreeding/inbreedin

Knowing background health is unfortunately not fool-proof especially in regards to conditions with polygenic modes of inheritance with any breeding method used. When linebreeding/inbreeding are used the risks DO increase. That is a lesson that should be learned when polygenic conditions that are normally incredibly rare in a population become widespread - like SM.

If dog breeds are to survive, the impact of individual's breeding programs, and how they relate to and impact on the population genetics situation within the full breed, have to be understood. COI is a tool that helps with that, and yes, lower COI litters (with members bred forward on) help to sustain genetic diversity in a closed gene pool breed, where as higher COI litters help to diminish it.

Oreo
Click to expand...


IN-BREEDING and CKCS


Thank you Oreo for your Post, I have just printed off the Ruffly Speaking Article and will be having a good read with a few Coffees.

You mentioned Dr Hellmuth Wachtell ,just about scared to say this ,since I'm not the Flavour of the Month at the Moment,but a number of years ago he was interested in the Cavalier Pedigrees I had collected of Cavaliers here in Britain who had Heart Trouble and wanted to compare them with the Cavaliers in Austria with Heart Trouble.

When he saw the Pedigrees ,he got back to me saying how IN-Bred they were , that no wonder there was Heart Problems in the Cavalier Breed.

You mentioned in your Post about Line/In-Breeding and SM .

All I know is that in the early 1980's there was quite a bit of Half/Brother ...Half/Sister Matings taking place in the Cavalier Breed.

The SM Problem was not being noticed really in Cavaliers till I think about the early 1990's ,so did the IN-Breeding in the 1980's contribute to the Spread of SM

There had been Mother to Son and Father to Daughter and full Brother to full Sister matings in the 1970's and the early 1980's as well.

Was all this In-Breeding involved in the SM Problem. I just don't know, the only thing I know about are the Cavaliers who were being In- Bred at the time I have mentioned.

I do know that when Liverpool University saw the Cavalier Pedigrees I'd sent them,the Researchers particularly mentioned about the High Degree of Homogeneity in the Pedigrees.

There is no getting away from the fact that Cavaliers are suffering from Two Serious Health Problems SM and MVD.

The fact just can't be denied that Approx 60 Cavaliers were MRI Scanned in Australia by Dr Child ,Neurologist , for Cavalier Breeders and at the February Sydney Club Meeting , and she had given a Presentation on SM and she had said that she had Screened approx 60 Dogs ,These were Breeding Screenings ,

None of the the Dogs Screened had any Clinical Symptoms . They were not Cases referred to her .

Of these Dogs 50% proved to a Syrinx on MRI ,in other words had SM.These Cavaliers were non-symtomatic.

I wonder how IN-Bred those Cavaliers were?

Bet
 
Bet said:
I wonder how IN-Bred those Cavaliers were?

Bet
Click to expand...

Bet, I am a great admirer of Dr. Wachtell. As a geneticist he has gifted dog breeders on the Canine Genetics list his time, and has, as well, learned to read and write in English to do so.

On the topic of how in-bred any single Cavalier at this moment is, that is or is not affected by SM or MVD . . . it would be interesting to know but it really would not speak to the point.

SM and MVD have been "set" in the breed accidentally while trying to achieve other (probably wonderful) traits. This seems to be long ago, and as they are already set and have now been shown to be breedwide, then high and low COIs in litters can not be relied upon to effectively predict chances of either of these conditions. They can crop up in either as the genes that cause them are higher in concentration in the full breed and we cannot yet tell in which exact dogs . . . . if only we could SEE genes.

The best predictor is going to be the health of the ancestors to the litter - including 'sideways' ancestors such as Uncles and Great Uncles (and Aunts). Unfortunately testing for SM has just recently begun in any amount, so particulars about health in ancestors (SM wise) are often not known as SM often remains non or barely symptomatic. I understand that in regards to MVD breeders have probably been keeping better track.

That still doesn't take away from the fact that a lower COI litter helps to sustain genetic diversity in a closed gene pool breed. This is beneficial for the full breed.

Helmuth Wachtell mentioned this point, and you posted it in your first post on this thread. It is an important concept.

Oreo
 
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Oreo said:
Rod, I don't believe there has been an assumption put out that inbreeding/linebreeding only makes lines worse, although I do believe there are some breeders that are defensive about this and that are possibly reading that assumption into every post on the topic. We all know that inbreeding/linebreeding has also been what has helped fix desirable traits.

Throughout the thread what has been mentioned is that "risks" are involved when using linebreeding/inbreeding, and that they have to be acknowledged instead of glossed over. I don't believe acknowledging those risks and how they have also negatively impacted dog breeds is a universal condemnation.

Prof. Bateson is well qualified and is very correct in bringing attention to this. These words of his, when speaking of disease, are spot on.

"In-Breeding tends to Fix Recessive Deleterious Traits and thereby Increase the Number of Animals in which the Disease is apparent" ...
Click to expand...

Thank you, Oreo, for all of this helpful information. My comments were in response to what seemed to be a one-sided viewpoint, attributed to Professor Bateson, that in-breeding universally only brings out the worst of the recessive traits. So, I don't dispute what you say, as much as state that I was not responding to that.

I certainly have no expertise. As everyone knows (and most are quick to remind me), I've never bred a Cavalier in my life. Although I have involuntarily mid-wifed the births of a few litters of piglets. Believe me, youngsters on farms soon become slave laborers, and it can be a messy, eye-opening experience. But I digress...

I had alway thought of line-breeding as a form of in-breeding.

I don't quite see how in-breeding explains CM and SM in this breed. To the contrary, one theory is that CM/SM and possibly MVD can be attributed to out-crossing, particularly to popular sires. Nevertheless, I can see how in-breeding could make existing CM/SM and MVD worse in later generations.
 
I was a child farm "slave" laborer myself Rod . . . and it has given me a lifetime of wonderful memories along with very unladylike cow milkers hands.:)

I have to ask what you mean by "outcrossing" when you use it in this sentence. "To the contrary, one theory is that CM/SM and possibly MVD can be attributed to out-crossing, particularly to popular sires." Are you talking of to a different breed, or are you talking of simply breeding to a different line, within Cavaliers?

Oreo
 
Oreo said:
I... I have to ask what you mean by "outcrossing" when you use it in this sentence. "To the contrary, one theory is that CM/SM and possibly MVD can be attributed to out-crossing, particularly to popular sires." Are you talking of to a different breed, or are you talking of simply breeding to a different line, within Cavaliers? ...
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I did not mean a different breed; I meant other blood lines.
 
I've not heard this theory and cannot imagine what the basis of it might be. Could you explain it?

I have read Clare Rusbridge's full thesis which does indicate, in words and diagrams, how some suspect recessives can be traced back to a couple of relatively early Cavaliers.

Oreo
 
Oreo said:
I've not heard this theory and cannot imagine what the basis of it might be. Could you explain it?

I have read Clare Rusbridge's full thesis which does indicate, in words and diagrams, how some suspect recessives can be traced back to a couple of relatively early Cavaliers. ...
Click to expand...

Well, sure. The disease, CM/SM, now is so widespread in the breed, as Dr. Rusbridge acknowledges in her thesis (page 167, for example) that it would appear that in-breeding now would have no greater affect upon CM/SM in future generations than would out-crossing to other bloodlines. This is not based upon anything that I recall reading on the subject. It is just that if 95% of Cavaliers really have the malformation, and 50% of those also have syrinxes, the breed is well past the detrimental affect that in-breeding would have on CM/SM in a bloodline.
 
I think we are singing from the same hymn sheet when speaking to the fact that CM/SM and MVD are already too well established in the breed. At this point a breeder's knowledge of ancestral health history is of the most importance.:)

Clare Rusbridge goes into more depth on heredity on page 153 of her thesis (diagram on page 152) where in the discussion portion she speaks to the inheritance of occipital bone hypoplasia and how it can be traced through to a key bitch. The diagram shows how it was possible for genes from this girl to match up in linebred progeny.

That is why I wondered about the explanation that CM/SM might be attributed to outcrossing. Maybe we are misunderstanding each other.

Oreo
 
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Oreo said:
... That is why I wondered about the explanation that CM/SM might be attributed to outcrossing. Maybe we are misunderstanding each other. ...
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If "Bitch G" in Dr. Rusbridge's dissertation (pages 153-154) was the -- or a -- founder of the recessive CM gene(s), in-breeding of her progeny certainly could have doubled-up the offending gene(s) by the time "Dog V" was produced, seven or more generations after Bitch G. But it would have been Dog V, who sired 57 litters in three years (1989 to 2001), who would qualify as the Popular Sire which sent the gene(s) "viral", so to speak. Mere in-breeding does not explain the widespread existence of CM. A lot of out-crossing needed to occur, as well, once the in-breeding set the stage. I would say that siring 57 litters in three years qualifies Dog V as a Popular Sire.

As bad as CM/SM is, I think there are merits, as well as demerits, to line-breeding. Bitch G, and the in-breeding which followed her, could have been a fluke, a horrible fluke, which started the CM gene(s). But that doesn't mean that every line-breeding creates only monsters. My role in this discussion started because Professor Bateson reportedly condemned all line-breeding. I just don't agree with that conclusion.
 
IN-BREEDING and CKCS

RodRussell said:
If "Bitch G" in Dr. Rusbridge's dissertation (pages 153-154) was the -- or a -- founder of the recessive CM gene(s), in-breeding of her progeny certainly could have doubled-up the offending gene(s) by the time "Dog V" was produced, seven or more generations after Bitch G. But it would have been Dog V, who sired 57 litters in three years (1989 to 2001), who would qualify as the Popular Sire which sent the gene(s) "viral", so to speak. Mere in-breeding does not explain the widespread existence of CM. A lot of out-crossing needed to occur, as well, once the in-breeding set the stage. I would say that siring 57 litters in three years qualifies Dog V as a Popular Sire.

As bad as CM/SM is, I think there are merits, as well as demerits, to line-breeding. Bitch G, and the in-breeding which followed her, could have been a fluke, a horrible fluke, which started the CM gene(s). But that doesn't mean that every line-breeding creates only monsters. My role in this discussion started because Professor Bateson reportedly condemned all line-breeding. I just don't agree with that conclusion.
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IN-BREEDING and CKCS

As far as I can understand it ,Professor Sir P.Bateson, only mentioned that Grand-Mother to Grand-Son, and Grand-Father to Grand-Daughter was In-Breeding.

I am wondering ,when Breeders talk about LINE BREEDING ,what do they mean.

I think I am right in saying that IN-BREEDING means in matings where a Common Ancestor does not occur behind Sire and Dam in 4-5 Generation Pedigree.

Is that right?

Could I add to my Post to thank Margaret for Posting on another Thread, mentioning that in the BBC Trust Complaint ,it was reported that it was probable that there were some Cavaliers affected with the Heart Disease in the 1950's and 1960's and that they were used extensively at Stud,

Also the Committee felt that , while the cause of SM was not known ,there was a Broad Concesus that IN-BREEDING play a Role in Spreading SM

Bet
 
Bet said:
...I am wondering ,when Breeders talk about LINE BREEDING ,what do they mean.

I think I am right in saying that IN-BREEDING means in matings where a Common Ancestor does not occur behind Sire and Dam in 4-5 Generation Pedigree.

Is that right?
Click to expand...

Apparently at least three different definitions of in-breeding, and two of line-breeding, are being used in the current discussions on this board as well as CC. The one I have been using for in-breeding is mating closely related breeding stock, while line-breeding is mating stock within the same pedigree, such as grand-father and grand-daughter.

So, to me, line-breeding is a form of in-breeding.

Added link: I just came upon this perfect example of line-breeding in today's issue of The Sun: "I'm In Love With My Grandson -- And We're Having A Baby!", at http://www.thesun.co.uk/sol/homepage/news/2954310/Gran-and-grandson-to-have-baby.html#ixzz0maSV2FzO

Bet said:
...Also the Committee felt that , while the cause of SM was not known ,there was a Broad Concesus that IN-BREEDING play a Role in Spreading SM ...
Click to expand...

I really don't see how in-breeding could possibly spread SM beyond one bloodline, since only one bloodline is involved in in-breeding. I can understand how in-breeding could bring SM gene(s) to the fore by doubling up on the recessive, but if you don't breed outside of your bloodline, you're not going to spread the genes to other bloodlines.
 
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RodRussell said:
Apparently at least three different definitions of in-breeding, and two of line-breeding, are being used in the current discussions on this board as well as CC. The one I have been using for in-breeding is mating closely related breeding stock, while line-breeding is mating stock within the same pedigree, such as grand-father and grand-daughter.

So, to me, line-breeding is a form of in-breeding.



I really don't see how in-breeding could possibly spread SM beyond one bloodline, since only one bloodline is involved in in-breeding. I can understand how in-breeding could bring SM gene(se) to the fore by doubling up on the recessive, but if you don't breed outside of your bloodline, you're not going to spread the genes to other bloodlines.
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Since the demise of the really big kennels, that had perhaps up to 60 dogs, all cavalier breeders have needed to introduce new blood in to their lines on some occasions.

The dogs are usually not shown, they are bought in, bred from and it will be their offspring, bearing the kennel name, that will
be seen in the show ring. The line continues to look completely inbred.

There is undoubtedly those that have carried out extremely close matings over very many generations. The problem is that when inherited problems have shown up they have been hidden, denied and ignored, nor were the affected cavaliers removed from the breeding programme.

Many, if not most, of these inbred lines had very serious issues with MVD or SM but their breeders have been the people that were, and in some cases still are, the loudest in denying the extent of the health problems in the breed.

They are the people who, perhaps unwittingly, have brought this breed to the state it is in now. They need to see what a desperate state cavaliers are in and, if they truly love the breed, they would cooperate with all the researchers and try and give this breed a future.

Line breeding or inbreeding is not now going to make a lot of difference in the case of MVD & SM, they are too widespread within all lines, but to maintain what little genetic diversity there is these practices should stop.
 
In-Breeding and CKCS

IN-BREEDING and CKCS

Line breeding or inbreeding is not now going to make a lot of difference in the case of MVD & SM, they are too widespread within all lines, but to maintain what little genetic diversity there is these practices should stop.[/QUOTE]


Can I mention about Margaret's Post.

I just can't remember whether I have mentioned this before or not, but maybe it's worth repeating again.

I had contacted the MVD Cavalier Researchers at Edinburgh University, telling them about how it's known that the Heart Problem had been in our Cavalier Breed since the 1940's, also that Cavaliers ,known to have Heart Condition were being used at Stud in the 1950's.

I asked ,if because of this there now could be many Cavaliers who were Carriers of the MVD Gene/Genes around to-day.

The word I got back ,was yes ,that they thought this was very probable,

Also I contacted Professor J .Bell , Geneticist at Tufts University ,America, and he also agreed about this, and said that the only way the Cavalier Breed could have a Future was not to Breed from Cavaliers before they were 2.5 years of age.

The Cavaliers are the only Toy Breed with an early On-Set of MVD, and the best chance for Cavaliers is to try and delay this early On-Set.

Unfortunately there are still some Cavalier Breeders making the excuse , OK you can MRI Scan for SM or Test for Heart Trouble at 2.5 years ,but those Problems can happen to the Cavalier at 4-5 yeras old.

I just don't know how to answer this attitude.

Any-body got any answers?
 
Bet said:
... Unfortunately there are still some Cavalier Breeders making the excuse , OK you can MRI Scan for SM or Test for Heart Trouble at 2.5 years ,but those Problems can happen to the Cavalier at 4-5 yeras old.

I just don't know how to answer this attitude.

Any-body got any answers?
Click to expand...

MVD Breeding Protocol

I have an answer regarding MVD, but that doesn't mean that anybody will listen to it. The goal of the MVD breeding protocol is to push back the age of onset of MVD to after the 5th birthday. The way the drafters of the protocol recommend doing that is to not breed any Cavalier until after its 5th birthday, and only then if it did not have a murmur prior to its 5th birthday and neither of its parents had a murmur prior to their 5th birthday. THAT is the real MVD breeding protocol. And THAT means no breeding at all before age five years.

The drafters recognized that very few breeders would be willing to wait for a dog to reach age five years before breeding it. So, they allowed an exception to the protocol: You may breed the Cavalier before its 5th birthday if it is at least 2.5 years old and has no murmur. The part of the protocol about the parents not having murmurs before age five years still would apply.

So, if breeders complain that a 2.5 year old with a clear heart could be bred, and then before its 5th birthday it could develop a murmur, tell them to wait to breed the dog until after its 5th birthday.

SM Breeding Protocol

As for CM/SM, the SM breeding protocol is trying to make the best of a miserable situation. We suspect that possibly up to 95% of the breed has CM and half of those Cavaliers have SM. An objective breeding protocol for that situation would include bringing in new blood from other breeds. But we can't do that, for a variety of reasons. So, we try to deal with this miserable situation as well as play by the breed standard and kennel club rules. So, we follow the existing SM breeding protocol, all the while recognizing the SM could progress later on.

If breeders sincerely are concerned about that SM protocol not working, then they should not breed Cavaliers at all. It certainly makes no sense for them to grouse about the SM breeding protocol not being enough, and then to ignore it and continue breeding CKCSs.
 
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