Genetics, Health And Breeding?

[Judy]

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As there were only 3 posts that I have found that I felt were breaking posting rules I have been able to remove them. I agree its a shame when whole topics have to be removed but here have been times when that happens due to the sheer amount of time it would take to go through them all, especially when other people insist on quoting the bad ones. It would be helpful if people reported threads when they stated getting out of hand instead of waiting for a moderator to find it so that they could be dealt with before the sheer volume of posts makes it unmanageable to go through each individual post selectively editing and deleting as is very often the case. Luckily someone else has just reported this to me.

 

[~elizabeth~]

I think I've followed all this ... so unless I've missed something (which I may well have done) ... what hasn't yet been explained is why does lowering genetic diversity compromise immunity? What mechanism is at work here?

It's quite complicated and long story, but I will try to make it short.

...

Our purebred dogs have already lost some of MHC complex variability off the whole species just because they are pure bred and have only a part of all canine genes. But we shouldn't cause further elimination of these very important genes.

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Thankyou Natalia for your clear explanation. :thumbsup: Many of us have observed health crashes happen over time in other breeds of domestic animals, and pray a similar situation never happens within whippets. Many of us have come to the breed because it has been one of the healthiest of the pure-bred dogs historically, and it would be heart-breaking if this ceases to be true in the future.

 

[Judy]

Yes, great post Natalia. Thanks for the explanation :thumbsup:

 

[T Hoare]

I must have missed something.

I have found this thread interesting and informative.

 

[chelynnah]

PLEASE don't let this thread get personal. This is not the place for it. I'm not suggesting hiding anything, but this board is not the place, and if someone has issues with a line or breeder, then please take it up with the people behind those lines. If someone knows of issues, then I'm sure that the people involved in those lines would appreciate knowing.

That said, I think that we do undertest in this country. I do believe that on the whole, and especially compared to other breeds, that whippets are overall a generally healthy breed, certainly free from a LOT of the inherited problems we see in other breeds. But I think the only way to confirm this IS with testing.

A lot of shows offer eye testing and hearing tests. I personally had Savannah and Teya eye tested at our local club a couple of years ago. Jaws dropped when I walked in with them and I was asked why do it, and my response was why not. Both have tested clear - which is what I expected, but until the test couldn't say with certainty.

If we don't test for things, then we don't have a baseline for instances in the breed for the time if/when something rears it's ugly head. All we can say is we didn't know about it, but we can't prove that it hasn't been a problem all along, and there's no real way to trace where it's come from. So personally I'm all for testing and keeping records.

Wendy

 

[marshall]

HALLO ALL. I HAVE READ THE HEALTH/GENETICS POSTS WITH GREAT INTEREST. I HAVE SHOWN AND BRED WHIPPETS FOR OVER 30 YEARS AND APART FROM THE ODD PUPPY WHO WAS'NT ENTIRE I HAVE NOT HAD ANY HEALTH PROBLEMS. CHECKING THE K.C. ACCREDITED BREEDER REQUIREMENTS WHIPPETS ARE NOT MENTIONED FOR ANY HEALTH SCREENINGS/TESTS WHICH MAY SUGGEST THAT EITHER BREED CLUBS HAVE'NT FLAGGED UP ANY ONGOING AND SERIOUS DEFECTS OR THAT THE K.C. IS OF THE OPINION THAT OUR BREED IS HEALTHY AND DEFECT FREE. SEVERAL YEARS AGO THE K.C. SENT OUT HEALTH QUESTIONNAIRES TO ALL BREED CLUBS AND PUBLISHED THE FINDINGS. I CAN'T REMEMBER THE OUTCOME ON WHIPPETS. PERHAPS SOMEONE OUT THERE HAS THE INFORMATION. HOWEVER, ANY SURVEY IS DEPENDENT ON HONESTY AND ACCURACY.

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edited to remove attached post which mixed in with this post

 

[maggie217]

I think I've followed all this ... so unless I've missed something (which I may well have done) ... what hasn't yet been explained is why does lowering genetic diversity compromise immunity? What mechanism is at work here?

It's quite complicated and long story, but I will try to make it short.

The immune system depends on something called MHC (major histocompatibility complex). MHC is responsible for marking all the cells of one's own body (so that they are not destroyed, marked as "own, ok") and for marking any invaders that might be in the organism, like bacteria, viruses etc. (so that can be destroyed by special cells, marked as "alien, danger!!!").

The problem is that any single cell, whose job is to mark own cells or invaders can recognize only very few similar paterns. And there are thousands and thousands of potential invaders to recognize, mark and destroy. That's why we have very, very many form of genes coding MHC complex. In humans we have a few hundreds (!) different alles for MHC complex, and every single individual has a unique combination of different forms.

Moreover, the genes for MHC are organized in very odd way, and the immune system cells are able to mix them and form different combinations of them, which enables marking more types of invaders. Because of that, if one part of the gene is lost, it means that many hundreds or thousands of possible invaders cannot be found, marked and fought.

As any individual has a unique set of MHC genes, it is quite unlikely that an important portion of possible combinations will be lost in random mating. Most individuals are hetorozygous for most genes in MHC complex, ie have one set from mother and another from father, being able to mark and fight the invaders of all the types. But inbreeding increases homozygocity. When mother's part is exactly the same as father's part, a puppy will have only half of the MHC genes it would have if the parents were unrelated (and have different sets of MHC genes).

That means, that probably it would be able to fight some of diseases quite well, but there will be some diseases it will be not able to fight at all, as it lacks cells able to mark the invader. This is exactly the situation observed in rats and mice strains in laboratories. Each strain is almost completely homozygous and very healthy itself (as all the lethal mutations were found and eradicated from the strain) but is prone to infections. That's why these animals have to be kept in very clean enviroment and not exposed to infections. Each strain is even labeled with the list of infections it's known to be unable to deal with!

The other, but related issue is that immune system markes not only alien cells, but own ones as well. If, by any chance, it's ability to recognize all types of own cells is compromised, some of the own cells may be marked as "alien, danger!!!" by mistake. That leads to autoimmune diseases. On the other hand, if MHC system's ability to mark own cells makes another mistake, cancer cells may be marked as "own, ok" and the cancer will develop without any problems. It's known that some strains os mice and rats are especially prone to certain types of cancer (well, they are breed to be prone).

Our purebred dogs have already lost some of MHC complex variability off the whole species just because they are pure bred and have only a part of all canine genes. But we shouldn't cause further elimination of these very important genes.

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Thanks very much for that explanation Natalia. That'a very a big hlp to my understanding. :thumbsup:

Pauline

 

[chelynnah]

HALLO ALL.  I HAVE READ THE HEALTH/GENETICS POSTS WITH GREAT INTEREST.  I HAVE SHOWN AND BRED WHIPPETS FOR OVER 30 YEARS AND APART FROM THE ODD PUPPY WHO WAS'NT ENTIRE I HAVE NOT HAD ANY HEALTH PROBLEMS.  CHECKING THE K.C. ACCREDITED BREEDER REQUIREMENTS WHIPPETS ARE NOT MENTIONED FOR ANY HEALTH SCREENINGS/TESTS WHICH MAY SUGGEST THAT EITHER BREED CLUBS HAVE'NT FLAGGED UP ANY ONGOING AND SERIOUS DEFECTS OR THAT THE K.C. IS OF THE OPINION THAT OUR BREED IS HEALTHY AND DEFECT FREE.  SEVERAL YEARS AGO THE K.C. SENT OUT HEALTH QUESTIONNAIRES TO ALL BREED CLUBS AND PUBLISHED THE FINDINGS.  I CAN'T REMEMBER THE OUTCOME ON WHIPPETS.  PERHAPS SOMEONE OUT THERE HAS THE INFORMATION.  HOWEVER, ANY SURVEY IS DEPENDENT ON HONESTY AND ACCURACY.
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edited to remove attached post which mixed in with this post

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There was a health survey done a couple of years back that was sent out through all the breed clubs. I don't remember the results from it, but someone else on here might.

Wendy

 

[beaker]

PLEASE don't let this thread get personal.  This is not the place for it.  I'm not suggesting hiding anything, but this board is not the place, and if someone has issues with a line or breeder, then please take it up with the people behind those lines.  If someone knows of issues, then I'm sure that the people involved in those lines would appreciate knowing.
That said, I think that we do undertest in this country.  I do believe that on the whole, and especially compared to other breeds, that whippets are overall a generally healthy breed, certainly free from a LOT of the inherited problems we see in other breeds.  But I think the only way to confirm this IS with testing. 

A lot of shows offer eye testing and hearing tests.  I personally had Savannah and Teya eye tested at our local club a couple of years ago.  Jaws dropped when I walked in with them and I was asked why do it, and my response was why not.  Both have tested clear - which is what I expected, but until the test couldn't say with certainty.

If we don't test for things, then we don't have a baseline for instances in the breed for the time if/when something rears it's ugly head.  All we can say is we didn't know about it, but we can't prove that it hasn't been a problem all along, and there's no real way to trace where it's come from.  So personally I'm all for testing and keeping records.

Wendy

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when one of my local clubs was short of attendants for eye testing i took Oto along to fill a place, i did feel a bit odd sitting there with him amongst the labradors and a couple of huskies though and the eye testing guy was a bit suprised to see a whippet there to

his registration papers were officially stamped (clear btw ) and i seem to remember him saying that results would be in the next breeds record suppliment.

it didn't take long to do and wasn't in any way upseting for Oto, though he did take a special interest in the guys beard and had a good snuffle of it when he peered into his eyes :lol:

 

[maggie217]

There was a health survey done a couple of years back that was sent out through all the breed clubs.  I don't remember the results from it, but someone else on here might.
Wendy

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I came across this health survey when considering getting a whippet. I don't know if it is the same one to which you refer Wendy. Not British, but interesting.

http://home.swipnet.se/whippetklubben/am_health.htm

Pauline

 

[BeeJay]

I think that you mean this.

KC health survey of whippets 2004

 

[maggie217]

I think that you mean this.
KC health survey of whippets 2004

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Yes that the one, I had just found the link for it but you beat me to it :thumbsup:

Pauline

 

[clayelem]

Thank you Natalia for the enlightening explanation.

 

[seaspot_run]

Thank you Natalia for the enlightening explanation.

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And from me as well.

 

[Eceni]

Thank you Natalia for the enlightening explanation.

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And from me as well.

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And, profoundly and completely, from me.... Karen gave us an entirely lucid, cogent view of why breeders prefer to line breed, and Natalie has enabled me to understand the genetic implications in a far greater depth than I have ever done before.

heartfelt thanks

m

 

[dragonfly]

It is well known that breeders feel very strongly about their lines, almost as though they were an extension of themselves. Of course the genes in our dogs come from their ancestors, we didn't invent them and there should be no shame or guilt if you have a health problem. Sadly many breeders don't see this and feel as though a health issue in their lines is a direct comment on their skills and integrity as a breeder, they therefore make no mention of it to the other breeders to the detriment of the breed as a whole.

The point that I really want to get across is that although there are definitely inherited health problems in our breed they are not yet at a high level and we still have time to do something about it. Most whippets are strong and healthy but this won't continue for ever if the breed as a whole does not tackle this issue.

I am open about things that have happened in my lines to the people who ask or who have an interest in a particular dog. I have talked about them in breed council. I cannot possibly give more details on this forum, it would be totally inappropriate as naturally enough there are other lines involved and therefore other people. Many breeders have produced stock that has health issues but relatively few talk openly about it.

Is there the will in this country to look at the potential of this problem before it is too late. As I have said before we can see what has happened to other breeds so we have the benefit of their experience. Practices which were appropriate to fix type in the early days of a breed are not necessarily appropriate as the gene pool reduces. Natalia's explanation shows us all very clearly why it is not safe to

line breed forever.

It is not a major issue now but it so easily could become one, and just as other breeds have run up cul de sacs, with problem genes in every dog, then so could our lovely breed. The whippet is not unique, it can happen to us too. Our advantage lies in the fact that the closed population that is the Whippet undoubtedly started off with a wider gene pool than many other breeds which is why it is still relatively healthy. It also means we can see what has happened to the other breeds and heed the warning they have provided.

Cathie

 

[~Annie~]

I think I've followed all this ... so unless I've missed something (which I may well have done) ... what hasn't yet been explained is why does lowering genetic diversity compromise immunity? What mechanism is at work here?

It's quite complicated and long story, but I will try to make it short.

The immune system depends on something called MHC (major histocompatibility complex). MHC is responsible for marking all the cells of one's own body (so that they are not destroyed, marked as "own, ok") and for marking any invaders that might be in the organism, like bacteria, viruses etc. (so that can be destroyed by special cells, marked as "alien, danger!!!").

The problem is that any single cell, whose job is to mark own cells or invaders can recognize only very few similar paterns. And there are thousands and thousands of potential invaders to recognize, mark and destroy. That's why we have very, very many form of genes coding MHC complex. In humans we have a few hundreds (!) different alles for MHC complex, and every single individual has a unique combination of different forms.

Moreover, the genes for MHC are organized in very odd way, and the immune system cells are able to mix them and form different combinations of them, which enables marking more types of invaders. Because of that, if one part of the gene is lost, it means that many hundreds or thousands of possible invaders cannot be found, marked and fought.

As any individual has a unique set of MHC genes, it is quite unlikely that an important portion of possible combinations will be lost in random mating. Most individuals are hetorozygous for most genes in MHC complex, ie have one set from mother and another from father, being able to mark and fight the invaders of all the types. But inbreeding increases homozygocity. When mother's part is exactly the same as father's part, a puppy will have only half of the MHC genes it would have if the parents were unrelated (and have different sets of MHC genes).

That means, that probably it would be able to fight some of diseases quite well, but there will be some diseases it will be not able to fight at all, as it lacks cells able to mark the invader. This is exactly the situation observed in rats and mice strains in laboratories. Each strain is almost completely homozygous and very healthy itself (as all the lethal mutations were found and eradicated from the strain) but is prone to infections. That's why these animals have to be kept in very clean enviroment and not exposed to infections. Each strain is even labeled with the list of infections it's known to be unable to deal with!

The other, but related issue is that immune system markes not only alien cells, but own ones as well. If, by any chance, it's ability to recognize all types of own cells is compromised, some of the own cells may be marked as "alien, danger!!!" by mistake. That leads to autoimmune diseases. On the other hand, if MHC system's ability to mark own cells makes another mistake, cancer cells may be marked as "own, ok" and the cancer will develop without any problems. It's known that some strains os mice and rats are especially prone to certain types of cancer (well, they are breed to be prone).

Our purebred dogs have already lost some of MHC complex variability off the whole species just because they are pure bred and have only a part of all canine genes. But we shouldn't cause further elimination of these very important genes.

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Thank you so much ... that is exactly the kind of answer I wanted ... clear, concise and a proper explanation :thumbsup:

Annie

 

[anniewhippet]

I think that you mean this.
KC health survey of whippets 2004

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sorry have only just caught up with this, some computer/connection probs still & a slow response.

However the above made interesting reading :thumbsup: but I was abit surprised at the numbers quoted;

846 forms sent out ? was that everybody in 2004?

374 back....thats a great pity (1 being me )

making a response rate of 44.2%

perhaps its about time we had another crack at this and urge everyone to sit down with a cuppa, or a glass of wine, and carefully fill it in before sending it back? Then perhaps we can draw any conclusions, or actions, needed?

 

[seaspot_run]

Cathie was certainly very honest with me when I bought Mabel. Actually, I knew about a problem she'd experienced with her grandmother's litters quite well already, because I had wanted to buy a puppy from the litter that Mabel's grandmother came from and since she ended up with low numbers, there wasn't a puppy for me there and I had to wait a few years for my Bluestreak Whippet.

Nonetheless a few helpful souls e-mailed me when they got wind I was buying Mabel convinced I would not have been aware that her grandmother had produced some cleft palates.

Of course I was aware of it, but as it was not a problem in any of my lines I intended to cross her into, it was a worthwhile risk for me given the added benefit of introducing some outcross vigor.

To be on the safe side, I supplemented Mabel with folic acid and she gave me three large litters and no cleft palates, but if I had seen any, at least I wouldn't have been confused about where to look first for answers. As time has gone on, it appears that this problem (which is probably not strictly genetic) has not really been an issue for the Bluestreak line, and it certainly has not been one for me so far in using it, but I did appreciate the candor.

Outcrossing is a risk, but if breeders are honest then you can bring in outside lines and at least make sure you're not bringing in anything that you're already trying to cross away from.

I think what's happening in Whippets is that we have finally reached critical mass in terms of how many purebred generations we are away from the original late-1800's crosses that created the modern breed. It's been over a hundred years now since outside blood was last added to the show gene pool and so the odds of certain defects from repeated closebreeding or injudicious outcrossing are greater. I recognize the risks for reproductive and immunity-based problems from repeated closebreeding are molecular biological in nature, as Natalie explained very well. There is a distinction to be made between those types of effects and the elimination of rarer defects which are single loci in nature. In the first case, outcrossing more will yield better results. In the latter, as with the example I gave several pages back, close crosses can be used to identify the original carriers and crosses that result in the manifestation of the defect, and then breed roughly within familiar lines in such a way that that cross is never repeated.

These topics have been raised quite often on US e-mail lists and message boards without people taking things as personal, and I hope the thread can continue in that vein.

At some point, we all need clean lines to go to fix faults, even if we think we have no health problems, so it's to everyone's benefit to help each other.

The prior info on the health survey is very interesting--would probably correlate very well with a similar sample size here in the US.

One concern I have in the US is that breeders often do not have sufficient time between generations to allow for problems to surface and be identified. There are sire lines over here where the great-grandsire is not even 7 years old. Each of the males in that line did big winning out of puppy class and probably finished at the specialty level before 15 months of age, and then were used, and then their best son did likewise, and so on, and so forth. It's hard not to be seduced into wanting a piece of such successful lineages, but I think that if we are serious about good health, we need to not be in such a rush to be the first to use an exciting young male, but instead look to those 10+ year old dogs who are still in good overall health.

In the interest of full disclosure, I have used a few very exciting young males, but I try not to make a habit of it. I'm much more comfortable using a dog who has at least made it to late middle age in good health. And I love to use a true Veteran.

Karen Lee

 

[almondjd]

bottom line:

line breeding is based on what you can see in a dog/bitch

It's what you *can't* see that causes the diseases we've been talking about - when all the recessives come together - but you didn't know they were there because they were recessive and so hidden

which is why it's generally not the case that you 'bring in ill health' by outcrossing to another (inbred) line - it's more that the match between the two lines shows up disease that was already there in both

does that make more sense?

would someone else like to help here?

m

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