Latest News On Syringomyelia In Cavalier King Charles Spaniels.

[shortstep]

That's what I thought, there is no clear correlation of presence of syrinx to manifestation of SM.

but wouldn't it be prudent to only breed from dogs where it was absent? sorry if i am asking dumb questions.

No not dumb at all.

It works is like this. I will just make up numbers and be very dramatic to make it easy to see.

You have a disease and it has multi genes and likely also to have what is called risk factors (which are genes that in themselves are not the disease but create a increased risk for the disease), and in the case of these we could be talking 3-20 genes directly in play.

There will also be an level of dispersion of the genes/disease in the breed. In something like this, it is likely that all dogs carry at least some of the genes, maybe many carry most of the genes and to me it also sounds very possible that there are also have risk factor genes in play. Might be genes that turn on or off, maybe hormones, nutrition, shape of skull and so on that will cause the disease to be expressed with more or less symptoms in each dog. So in effect there are no dogs to breed that are not at risk of producing the disease.

So yes breeding only the A dogs means that 3 out 4 will be normal, but more importantly it also shows that all normal dogs are still producing the disease (the 1 in 4 that is affected). This is important.

So now you need to look at the total number of dogs that are A vs the number that are B or C and so on in the population. Lets be dramatic and say only 10% are A and we remove the other 90% of the population. We had 1000 dogs to choose from, now we have 100. And we know that these 100 will still produce 25% affected pups and there is no reason not to believe that their normal pups will also produce 25% affected pups.

Now say all the above again, but this time for a second disease, MVD. But now you only have the remaining 100 dogs left in the population to apply it to. After screening the 100 dogs you find you have 10% perfect hearts at 5 years of age, so you remove the other 90% of dogs from breeding. You now have 10 dogs left in the population, and those 10 dogs will still produce 25% SM and some % of MVD.

You just wiped out the breed and did not solve the problem. Even if the reduction numbers were not as dramatic as I made them, say in the 50% range that needed to be removed, the end result would be the same. I know one breed a 25% carrier rate in a simple recessive gene disease with DNA testing, no dogs are removed, even affected can be bred but they must be bred to normal. thisis done to keep as many dogs as possible in the gene pool.

Also population genetics tells us that when ever you reduce the population # you will also increase the chance of disease and you will also will bring out other hidden diseases that were not a problem when you started.

The best thing to do in any population, but especially in these situations where several complex diseases are present, is to attempt to keep the population as big as possible without increasing the problems.

So yes, screening for both disease, but also looking at other heath problems that are at lower dispersion rates in the breed to try to prevent them from increasing and also looking at general health and vitality. You would need to be looking at inbreeding rates. Everything has to be weighted out, and you will have to allow some give and take to make the best selection of dogs for each breeding.

Just a personal opinion, I would also add that even if they find a DNA tests (which is very unlikely at this time) if you had wiped out the population prior to finding the test, the test would then have little impact in saving the breed. You would have several other disease problems in large numbers to face down again. So you simply jumped out of the pan and directly into a blazing fire.

Please remember I made up these numbers to be dramatic to show the process. They are not reflective of what the numbers are in this breed, which I am sure are not even close to being as dramatic in Australia. Sorry for being long winded, that must have taken 15 mins for me to type! LOL

Edited November 15, 2010 by shortstep

[Jaxx'sBuddy]

Comparative tests are time consuming, and unless the person doing it was competent then it would be a waste of time. If one of the anti-breeder researchers did it the outcome would be biased as they'd be only looking for what proves their theory. Good research is never easy but it is doable. Choosing the factors to include is the hardest part. I did one as an assignment in uni, looking at birds colouring, either monochromatic (both sexes identical) or dichromatic (sexes different). In that case I looked at all life history traits, eg age to maturity as well as environmental, diet etc. You need a nice long list so you can see if your species tends to fall into certain groups, for example lorikeets would fit into the highly social category. So if you found lots of other species that were monochromatic had large social groups you could conclude that they were correlated. It would rely on breeder honesty as well as good empirical data.

TY Rev JO , there is lots to think about in your post and it seems it would need to be a long term study as well as complicated.

[Are You Serious Jo]

Now don't forget there are limits on inbreeding coefficients, so if you do happen to stumble on a line free of some genetic disease you can't work towards growing that line, they will force you to outcross and bring in the deleterious genes again. If you take out enough dogs through breeding exclusion and don't allow inbreeding then that breed will be gone. Because we don't have SM as such a problem in Australia then the people who are hysterical about it will destroy a breed because of a problem that exists in another country.

[shortstep]

Now don't forget there are limits on inbreeding coefficients, so if you do happen to stumble on a line free of some genetic disease you can't work towards growing that line, they will force you to outcross and bring in the deleterious genes again. If you take out enough dogs through breeding exclusion and don't allow inbreeding then that breed will be gone. Because we don't have SM as such a problem in Australia then the people who are hysterical about it will destroy a breed because of a problem that exists in another country.

Two very good points!

[Jaxx'sBuddy]

That's what I thought, there is no clear correlation of presence of syrinx to manifestation of SM.

but wouldn't it be prudent to only breed from dogs where it was absent? sorry if i am asking dumb questions.

No not dume at all.

It works is like this. I will just make up numbers and be very dramatic to make it easy to see.

You have a disease and it has multi genes and likely also to have what is called risk factors (which are genes that in themselves are not the disease but create a increased risk for the disease), and in the case of these we could be talking 3-20 genes directly in play.

There will also be an level of dispersion of the genes/disease in the breed. In something like this, it is likely that all dogs carry at least some of the genes, maybe many carry most of the genes and to me it also sounds very possible that there are also have risk factor genes in play. Might be genes that turn on or off, maybe hormones, nutrition, shape of skull and so on that will cause the disease to be expressed with more or less symptoms in each dog. So in effect there are no dogs to breed that are not at risk of producing the disease.

So yes breeding only the A dogs means that 3 out 4 will be normal, but more importantly it also shows that all normal dogs are still producing the disease (the 1 in 4 that is affected). This is important.

So now you need to look at the total number of dogs that are A vs the number that are B or C and so on in the population. Lets be dramatic and say only 10% are A and we remove the other 90% of the population. We had 1000 dogs to choose from, now we have 100. And we know that these 100 will still produce 25% affected pups and there is no reason not to believe that their normal pups will also produce 25% affected pups.

Now say all the above again, but this time for a second disease, MVD. But now you only have the remaining 100 dogs left in the population to apply it to. After screening the 100 dogs you find you have 10% perfect hearts at 5 years of age, so you remove the other 90% of dogs from breeding. You now have 10 dogs left in the population, and those 10 dogs will still produce 25% SM and some % of MVD.

You just wiped out the breed and did not solve the problem. Even if the reduction numbers were not as dramatic as I made them, say in the 50% range that needed to be removed, the end result would be the same. I know one breed a 25% carrier rate in a simple recessive gene disease with DNA testing, no dogs are removed, even affected can be bred but they must be bred to normal. thisis done to keep as many dogs as possible in the gene pool.

Also population genetics tells us that when ever you reduce the population # you will also increase the chance of disease and you will also will bring out other hidden diseases that were not a problem when you started.

The best thing to do in any population, but especially in these situations where several complex diseases are present, is to attempt to keep the population as big as possible without increasing the problems.

So yes, screening for both disease, but also looking at other heath problems that are at lower dispersion rates in the breed to try to prevent them from increasing and also looking at general health and vitality. You would need to be looking at inbreeding rates. Everything has to be weighted out, and you will have to allow some give and take to make the best selection of dogs for each breeding.

Just a personal opinion, I would also add that even if they find a DNA tests (which is very unlikely at this time) if you had wiped out the population prior to finding the test, the test would then have little impact in saving the breed. You would have several other disease problems in large numbers to face down again. So you simply jumped out of the pan and directly into a blazing fire.

Please remember I made up these numbers to be dramatic to show the process. They are not reflective of what the numbers are in this breed, which I am sure are not even close to being as dramatic in Australia. Sorry for being long winded, that must have taken 15 mins for me to type! LOL

thank you for taking the time to educate me shortstep ;). making the numbers dramatic helped show me the effects and your post was very informative.

i am a problem solver so when i see topics like this i start thinking "what can we do to make this situation better" because i never think anything is hopeless.

it does seem that this is a very complex issue but i go by the saying that you eat an elephant one bite at a time

so it seems to me we need to look at were to take the first bite.

it is important to remember that even 2 A's have a 25% chance of producing an affected pup.

how would we go about making it better for this breed and the people who want cavs as pets?

Edited November 15, 2010 by Jaxx'sBuddy

[Jaxx'sBuddy]

Now don't forget there are limits on inbreeding coefficients, so if you do happen to stumble on a line free of some genetic disease you can't work towards growing that line, they will force you to outcross and bring in the deleterious genes again. If you take out enough dogs through breeding exclusion and don't allow inbreeding then that breed will be gone. Because we don't have SM as such a problem in Australia then the people who are hysterical about it will destroy a breed because of a problem that exists in another country.

ahhh!!!! i get it, ty

would it make sense to scan all breeding dogs here to prove there is limited or no issue in australia?

if that was the case wouldn't it mean the cavs here could be used overseas as part of a breeding program to reduce the incidence?

although we still wouldn't know what is causing the issue.

[shortstep]

That's what I thought, there is no clear correlation of presence of syrinx to manifestation of SM.

but wouldn't it be prudent to only breed from dogs where it was absent? sorry if i am asking dumb questions.

No not dume at all.

It works is like this. I will just make up numbers and be very dramatic to make it easy to see.

You have a disease and it has multi genes and likely also to have what is called risk factors (which are genes that in themselves are not the disease but create a increased risk for the disease), and in the case of these we could be talking 3-20 genes directly in play.

There will also be an level of dispersion of the genes/disease in the breed. In something like this, it is likely that all dogs carry at least some of the genes, maybe many carry most of the genes and to me it also sounds very possible that there are also have risk factor genes in play. Might be genes that turn on or off, maybe hormones, nutrition, shape of skull and so on that will cause the disease to be expressed with more or less symptoms in each dog. So in effect there are no dogs to breed that are not at risk of producing the disease.

So yes breeding only the A dogs means that 3 out 4 will be normal, but more importantly it also shows that all normal dogs are still producing the disease (the 1 in 4 that is affected). This is important.

So now you need to look at the total number of dogs that are A vs the number that are B or C and so on in the population. Lets be dramatic and say only 10% are A and we remove the other 90% of the population. We had 1000 dogs to choose from, now we have 100. And we know that these 100 will still produce 25% affected pups and there is no reason not to believe that their normal pups will also produce 25% affected pups.

Now say all the above again, but this time for a second disease, MVD. But now you only have the remaining 100 dogs left in the population to apply it to. After screening the 100 dogs you find you have 10% perfect hearts at 5 years of age, so you remove the other 90% of dogs from breeding. You now have 10 dogs left in the population, and those 10 dogs will still produce 25% SM and some % of MVD.

You just wiped out the breed and did not solve the problem. Even if the reduction numbers were not as dramatic as I made them, say in the 50% range that needed to be removed, the end result would be the same. I know one breed a 25% carrier rate in a simple recessive gene disease with DNA testing, no dogs are removed, even affected can be bred but they must be bred to normal. thisis done to keep as many dogs as possible in the gene pool.

Also population genetics tells us that when ever you reduce the population # you will also increase the chance of disease and you will also will bring out other hidden diseases that were not a problem when you started.

The best thing to do in any population, but especially in these situations where several complex diseases are present, is to attempt to keep the population as big as possible without increasing the problems.

So yes, screening for both disease, but also looking at other heath problems that are at lower dispersion rates in the breed to try to prevent them from increasing and also looking at general health and vitality. You would need to be looking at inbreeding rates. Everything has to be weighted out, and you will have to allow some give and take to make the best selection of dogs for each breeding.

Just a personal opinion, I would also add that even if they find a DNA tests (which is very unlikely at this time) if you had wiped out the population prior to finding the test, the test would then have little impact in saving the breed. You would have several other disease problems in large numbers to face down again. So you simply jumped out of the pan and directly into a blazing fire.

Please remember I made up these numbers to be dramatic to show the process. They are not reflective of what the numbers are in this breed, which I am sure are not even close to being as dramatic in Australia. Sorry for being long winded, that must have taken 15 mins for me to type! LOL

thank you for taking the time to educate me shortstep ;). making the numbers dramatic helped show me the effects and your post was very informative.

i am a problem solver so when i see posts like this i start thinking "what can we do to make this situation better" because i never think anything is hopeless.

it does seem that this is a very complex issue but i go by the saying that you eat an elephant one bite at a time

so it seems to me we need to look at were to take the first bite.

it is important to remember that even 2 A's have a 25% chance of producing an affected pup.

how would we go about making it better for this breed and the people who want cavs as pets?

I do not think there is any evidence that we in Australia are having large numnbers of dogs with SM. No one is reporting that. So I think we need calm down and let the experienced breeders lead the way.

The only thing I wondered about (in either the UK or OZ population), and I kept asking Bet and Jessie if there wre any A dogs that were not producing 25% affected? I think this is good place to start looking for some possible ideas. But there was never any answer. It does not sound like dogs here are producing 25% affected (even from the untested breeding).

Anyway it is the Oz breeders that will know which way to head.

[Are You Serious Jo]

I think you'd have to compensate breeders if you mandated that, because it is costly and SM isn't a big problem. If no compensation was available then a lot of small breeders would walk away, again losing valuable dogs and data. I think if we could determine more about SM in our dogs then they could be used over in the UK. One of the biggest hurdles though is the anti-breeder mentality bought about by hysterics and PDE. That battle is as big as the one to understand SM.

[Jaxx'sBuddy]

i agree the oz breeders have the experience and not being disrespectful to any of them i would want to know they can be brutally honest about what is happening which can be hard if you are very close to a situation.

we don't want to lose dogs from the gene pool or have breeders walk away, enough are doing this already over other reasons

if the cav breed is going to stay around then i believe we do need to take this sort of issue seriously but gosh it is a complex problem

[shortstep]

I havent compared the odds of getting a pup with HD if the parents score zeros.Though it does lower over time if only zeros are used.

What OFA recommends is it is more important to look at the total family gentic picture than the score of the dog being bred (excluding dysplastic dogs). Another words if all the siblings had been scored and all were in the normal range, any of the siblings would have the same impact on future generations. Have both parents from the same all siblings normal litters, then add a few generations of the same all normal litters, they say you can reduce the number of affected dogs and reduce the hip scores over all. Looking at any one dog without knowing the silbings scores is not as effective.

This works well in the US where dogs are not put under and xrays only cost $50.00, lots of breeders are doing this (they pay for the xrays) and they think it is helping. Here where the vets put the dogs under and change several hundrend dollars or more to take the xray and even the reading is now close to $100.00 it is just not practical. Which is a real shame, and it will affect hip health in this country over time. A good example that all players including vets (not just breeders) need be active in the process if dog health is to improve.

Edited November 15, 2010 by shortstep

[Jaxx'sBuddy]

I havent compared the odds of getting a pup with HD if the parents score zeros.Though it does lower over time if only zeros are used.

What OFA recommends is it is more important to look at the total family gentic picture than the score of the dog being bred (excluding dysplastic dogs). Another words if all the siblings had been scored and all were in the normal range, any of the siblings would have the same impact on future generations. Have both parents from the same all siblings normal litters, then add a few generations of the same all normal litters, they say you can reduce the number of affected dogs and reduce the hip scores over all. Looking at any one dog without knowing the silbings scores is not as effective.

This works well in the US where dogs are not put under and xrays only cost $50.00, lots of breeders are doing this (they pay for the xrays) and they think it is helping. Here where the vets put the dogs under and change several hundrend dollars or more to take the xray and even the reading is now close to $100.00 it is just not practical. Which is a real shame, and it will affect hip health in this country over time. A good example that all players including vets (not just breeders) need be active in the process if dog health is to improve.

now that is really interesting. i have often wondered why all dogs need a GA for some xrays. i can tell my dog to lay down and stay and she wont move...she could have an xray without a GA i suspect.

[Steve]

I would feel better if more scans were done and the results published so breeders can say with confidence its not a problem here but the evidence says it is in this country and how prevalent it is needs investigating in my opinion. If its not a problem here and the breeders seem pretty confident its not than we may just have the answer for the UK breeders. But how do we know if we dont test?

[Jaxx'sBuddy]

I would feel better if more scans were done and the results published so breeders can say with confidence its not a problem here but the evidence says it is in this country and how prevalent it is needs investigating in my opinion. If its not a problem here and the breeders seem pretty confident its not than we may just have the answer for the UK breeders. But how do we know if we dont test?

steve that was what i was trying to say...what if we had the solution here?

i think the scanning and keeping a record of the results would be a good start to any possible solution even if it wasn't a conclusive test at least we would have more information than we have now which can only be a good thing for the breed.

eta maybe the UK breeders could look at other countries to see if SM was a problem or not elsewhere. seems to me we need data at the moment from as many places as possible

Edited November 15, 2010 by Jaxx'sBuddy

[LizT]

Unfortunately we also must take into account the fact that not every dog that is 'cleared' via scanning is necessarily going to be a good candidate for breeding, curtesy of other issue besides health, including conformation faults for eg.

There is a great risk of a shrinking registered dog gene pool that could eventually do more damage than SM ever would.

That then leaves "natural selection" among the BYB's dogs. And 'those that control things and think they know better" left calling for the opening of stud books to unregistered dogs to increase the gene pool.

A real can of worms IMO.

[Steve]

Unfortunately we also must take into account the fact that not every dog that is 'cleared' via scanning is necessarily going to be a good candidate for breeding, curtesy of other issue besides health, including conformation faults for eg.

There is a great risk of a shrinking registered dog gene pool that could eventually do more damage than SM ever would.

That then leaves "natural selection" among the BYB's dogs. And 'those that control things and think they know better" left calling for the opening of stud books to unregistered dogs to increase the gene pool.

A real can of worms IMO.

This is true but it would still be good to know the status of all possible info when you are making decisions.

[Dellcara]

This is true but it would still be good to know the status of all possible info when you are making decisions.

There are already some breeders who will not use unscanned dogs, and there are others doing their best to be within the current protocol.

There are quite a few "A" graded Stud Dogs around the country. No breeder I have spoken to here that I know has MRI'd dogs has "hidden" the results from others.

[Jaxx'sBuddy]

This is true but it would still be good to know the status of all possible info when you are making decisions.

There are already some breeders who will not use unscanned dogs, and there are others doing their best to be within the current protocol.

There are quite a few "A" graded Stud Dogs around the country. No breeder I have spoken to here that I know has MRI'd dogs has "hidden" the results from others.

txs dellcara, that is very good news. it would be great if everyone did the same.

i was just wondering if this might be something we could really use to differentiate good registered breeders from byb. i am not sure its just an idea that came to me, ie byb dont scan registered breeders do.

[Jaxx'sBuddy]

Unfortunately we also must take into account the fact that not every dog that is 'cleared' via scanning is necessarily going to be a good candidate for breeding, curtesy of other issue besides health, including conformation faults for eg.

There is a great risk of a shrinking registered dog gene pool that could eventually do more damage than SM ever would.

That then leaves "natural selection" among the BYB's dogs. And 'those that control things and think they know better" left calling for the opening of stud books to unregistered dogs to increase the gene pool.

A real can of worms IMO.

very true. even though it is a can of worms i think we need to grasp the nettle and try to think of what could be done with the least amount of harm to all concerned.

it is a tough situation for all involved.

[shortstep]

Hope the formatting works.

I found this on the Finnish KC site.

Now best I can figure this is one group maybe one years worth of dogs tested.

Finland has one of the best repuations for quality breeding programs, they do almost all of the most current methods, such as EBV, lots of screening.

Breeds each have a panel of experts and together they develop plans for each disease, overall heath, inbreeding (they have small populations usually) and all sorts of things. They are often held up as a model for progressive dog breeding.

I would guess that their cavs have a close connection to the UK bloodlines but they do import from all over the world to imporve their lines.

I did not think it looked near as bad as portrayed. I also note they do not only say to breed A to A, they have a range of options to keep most of the dogs in the breeding gene pool as I would have expected. The MVD rates also look way better then I thought they were.

Here is the link

http://translate.google.com.au/translate?j...nveto092010.pdf

[LizT]

Unfortunately we also must take into account the fact that not every dog that is 'cleared' via scanning is necessarily going to be a good candidate for breeding, curtesy of other issue besides health, including conformation faults for eg.

There is a great risk of a shrinking registered dog gene pool that could eventually do more damage than SM ever would.

That then leaves "natural selection" among the BYB's dogs. And 'those that control things and think they know better" left calling for the opening of stud books to unregistered dogs to increase the gene pool.

A real can of worms IMO.

This is true but it would still be good to know the status of all possible info when you are making decisions.

Absolutely. And hopefully with the more scanning being done the more affordable it will become.

Unfortunately it's not just the scanning costs that are the problem, there also has to be a technician who knows how to read results accurately. No-one will benefit from incorrect data either.