Line breeding and outcrossing -a paper

[Eceni]

The broad point remains that the act of line breeding - of striving for a notional 'breed purity' - in and of itself causes physiological weaknesses in the dog. .

how and when they arise is less the point than accepting the concept that at some point, if the breed registries don't open their stud books and allow some heterogenicity to reappear in the blood lines (more recipes in the cake to use the poodle and the chocolate cake analogy) then the health of all breeds will deteriorate. 

PRA, hip dysplasia (which seems to me to be increasingly prevalent, and the failure to test for it because there are 'no physical signs' is strange to say the least -by the time any one of us can see it - even if we spend our lives looking at lameness and can pick out a 1/10 lame dog at a distance of 50 yards - it's late in the day to start doing something about it), Familial nephropathy, the entire allergy spectrum from auto-immune disease to reactions to vaccinations to the flip-side of the dysfunctional immune system which is the failure to mount an adequate immune response to infections - all of these are enhanced, increased and multiplied by the practise of close generational breeding.

the point of the paper is to endeavour to put that across - worrying about specifics is good and laudable, but won't hold back the flood for any significant length of time.   Rather like global warming and peak oil, we can change our lightbulbs, which isn't a bad thing, but what's needed is a radical change of lifestyle.  So with breeding - the foundations need to change.  There is no 'magic bullet' but genetics is far more science than art, and can be incorporated in the art-more-than-science of dog breeding to the betterment of the individual puppies produced.  (and yes, we need to educate prospective owners in diet, animal behaviour and basic first aid, that's a given, but breeding for soundness must be the start).

e

[workingcockers]

PRA, hip dysplasia (which seems to me to be increasingly prevalent, and the failure to test for it because there are 'no physical signs' is strange to say the least -by the time any one of us can see it - even if we spend our lives looking at lameness and can pick out a 1/10 lame dog at a distance of 50 yards - it's late in the day to start doing something about it), Familial nephropathy, the entire allergy spectrum from auto-immune disease to reactions to vaccinations to the flip-side of the dysfunctional immune system which is the failure to mount an adequate immune response to infections - all of these are enhanced, increased and multiplied by the practise of close generational breeding.

But many of us do test for these things and take the test results into consideration in the cake mix!! If you read back some of my previous posts over the years and those of others, we have voiced concern many times about popular sires etc, the value in testing etc.

How would you propose to open up the gene pool? I for one do not want an official split in the KC register between the 2 types - we may need each other in the future, but what breed do you propose that we went to for more genetic material? It would be a minefield of more genetic probs - for example if we crossed with WSS we could bring in epilepsy which the mode of inheritance hasnt been establised as yet, a higher degree of HD and incidence of glaucoma, if we went to ESS they have their form of pra and im sure I read somewhere that it was suspected that 80% were carriers or affected based on a sample group. Field spaniels are a no go as they have such a tight gene pool which has been enhanced by ESS blood in the past, Sussex are in much teh same boat ditto clumbers  - so I think the specifics are actually very important!! I cannot see the point in bringing in fresh genes if they come with more baggage than we have already!! If we were to use these breeds, then it will be a long way down the line to wait until all teh DNA tests have been developed, used and then selecting only clear dogs to use in a breeding programme and some of course are conditions which are not straight forward gene mutations (HD). I dont see this happening 'soon' or even in my lifetime to be honest


PRA occurs in other breeds of course, but isn't FN a cocker confined mutation?

You can look up FN pedigrees and follow the lines almost to where and when the mutation occurred,  and where and when the disease crossed over from the particolour show lines into the solids.

John

Yes - I am aware of this and the dog in question where the mutation is thought to have occured. It was thanks to the show fraternity and their efforts (and one in particular) that raised funding and provided samples for the scientists to find the mutation. The test has only been available for a short time. Without breeders pushing, fund raising and providing DNA, these tests would not be here so quickly.

I attended the KC/BVA symposium 2005 and asked questions when the speakers were talking about genetics  and the genome project - I cant remember specifically what I asked but the answer was from the time of the split of the breeds to the current day was just a blink in the eye in the lifetime of a gene..

[KellyS]

Have to say I am finding this thread really interesting... I do not have the scientific knowledge that some of you have (doing an A-level in Biology which included a big chunk on genetics helps) and I am certainly learning all the time. I do agree with the points 'workingcocker' makes..

What do you propose, we start crossing show type cocker's with workers or other spaniel breeds?? That could bring a whole host of other problems aswell as losing type.

Cocker Spaniels are the 2nd most popular breed in the country, with the huge numbers registered every year there is going to be a higher proportion of problems... a Huge amount from those BYB's and commercial kennels.

The average Heinz 57 isn't without problems either, many cross breeds suffer with hereditary conditions despite not being line-bred.

I think line-breeding has it's place but should be done with extreme caution taking great care on which dogs you double up on....

[Helen]

..what do you propose, we start crossing show type cocker's with workers or other spaniel breeds?? That could bring a whole host of other problems aswell as losing type.

but  that is happening more and more and more ....look at all the 'unusual' colours now appearing more commonly in show lines - particularly the liver ones....that isn't happening without a good dollop of working cocker along the way... 

I'm not saying that this is from 'good' breeders, but it is definitely on a sharp increase....

[spanielcrazy]

I went through a phase of beating this drum loudly (about 25 years ago), coming out of a breed that had a very small gene pool (Doberman Pinschers--most American Dobermans can trace back to about 8 original dogs brought out of Germany before the war) By scientific definition, this breed, and many others with equally small or smaller gene pools should have died off by now due to the effects of "inbreeding depression". However this is not the case, they continue along, and while the breed certainly has it;s share of genetic problems, it continues to function and even flourish. There are many many other breeds in the same boat, and some with an even smaller gene pool.

There is a group of lions in Africa that have been much studied, they live in a huge valley created by an extinct volcano and are genetically cut off from the rest of the lion population. They are what we would call heavily linebred, with quite a bit of inbreeding thrown in--all by Mother Nature--and by "scientific" standards they should not exist anymore, let alone continue to dominate their little corner of the world. Nature has not seen fit to have them decide to breed to leopards. Cheetahs are in the same boat, and by genetic science should be dying off of all sorts of genetic defects; this has not happened with them either.

I have also worked with dogs in a professional capacity (as a vet nurse and a professional groomer) that I don't buy the theory of hybrid vigor ("mutts are healthier") I've seen many mixed breeds, coming from many generations of mixed breeds, with problems that would be considered genetic in a purebred.

The problem is not with the practice of linebreeding, inbreeding or outcrossing in themselves; They are valuable and necessary tools; it's where the focus of those practices lie. Is it to make money? Is it just to produce bench or field winners?

We are fortunate in cockers that we do have a diverse gene pool, what with partis, solids and workers, they represent 3 distinct different pedigrees (and in no way do I support splitting them into separate breeds!) We can weave outcrosses in our pedigrees without having to go out of the breed, and we are certainly not a breed that is in such trouble that it is necessary to go out of the breed to bring in "new fresh blood". And where would you go? As has been stated before, springers have genetic problems in common with cockers, plus a few of their own that would inevitably come along for the ride. And in strictest genetic terms, any of the spaniels would not be a true outcross, as they were all the same breed till the late 1800s, with smaller puppies used for heavy cover and wookcock (hence the cocker) and larger ones designated for springing birds and game (springers). And it's only been about 60 years since the breed that we know split in half--into English and American Cockers (due to an internal dispute about type and heads).

Combine our diverse gene pool with the wonderful testing available to us now through Optigen, (and I'm sure more new breakthroughs in the future) and we have a good amount of tools available to us to keep our breed strong and healthy!

[emilyjw]

I'm finding this interesting too, as a complete lay person, with no breeding experience or scientific background..

..what do you propose, we start crossing show type cocker's with workers or other spaniel breeds?? That could bring a whole host of other problems aswell as losing type.

but  that is happening more and more and more ....look at all the 'unusual' colours now appearing more commonly in show lines - particularly the liver ones....that isn't happening without a good dollop of working cocker along the way... 

I'm not saying that this is from 'good' breeders, but it is definitely on a sharp increase....

Bracken is a complete example of this and she is liver roan. Her breeder made the decision to breed liver to liver purely with the intention of getting a litter of liver roan pups which I guess are more fashionable/ saleable. We didn't realise this at the time.

IMO - I think it's the larger commercial breeders/puppy farms who are doing a lot of this cross-breeding. Bracken also has a fair amount of common relatives in her pedigree and I very much doubt this was because they were excellent examples, more likely they had the right colour, were easily available etc. What have I ended up with - a gorgeous cocker who is nowhere near breed standard, looks like a mixture of worker and show (she certainly wouldn't stand a chance in a proper show..).

From my impressions of the breeders that I have spoken to on this site, they are caring breeders striving to improve breed standards and maintain a healthy gene pool. But like someone said, the majority of cockers out there come from puppy farms, commerical breeders and BYB's who often care little about these factors. I wonder if we'll get to a point where the cockers that are shown look quite different from those from the above mentioned places, especially as more mixes of working and show appear.  It's amazed me how many more liver roans have appeared on the boards since we got Bracken, they seem to be becoming more and more available and I wonder if that is because some breeders are choosing colour over other factors...

[Eceni]

Hi - this article is related to Australian Shepherds, but I think you'll find it answers the 'cheetah' question rather effectively and continues to ask the questions that we're asking here...

http://www.ashgi.org/articles/breeding_incest.htm

good luck, all

m

[Eceni]

so..... is FN in the working lines yet?  I haven't come across it, but then perhaps I don't look hard enough

thanks

e

[tiamaria]

like someone said, the majority of cockers out there come from puppy farms, commerical breeders and BYB's who often care little about these factors. I wonder if we'll get to a point where the cockers that are shown look quite different from those from the above mentioned places, especially as more mixes of working and show appear. 

This is something i have often wondered.  My mother in law who loves KCS said to me a couple of weeks ago after visiting the cheshire dog show, that the ones she seen there are the ones she likes - someone she kinda knows breeds them and she thinks his looks nothing like them, his have long bodies and their heads arnt as nice.  Same with my partner not wanting another cocker spaniel earlier in the year because the ones he always sees out and about have long bodies and quite long faces and look nothing like our old cocker Rosie. 

[Roslyn McConnell]

I find everyone's comments here fascinating!!!

As a genetist myself I have felt torn between my love of this breed and what I know about the damaging effects of inbreeding.

I found a few anomalies in the article but I think thats due to it being written so long ago and the fast pace of research.

I have to admit I did not know that some people actually recommend inbreeding of close relatives......while I understand the desire to have consistency in breed standard, breeding a bitch to her grandfather etc is just asking for trouble and in my opinion this sort of partice should be banned. Dogs after all are mammals like us, their DNA is structured the same as ours, made up of the same 4 bases and functions in the same way therefore the laws of inbreeding (for planned litters anyway) should apply to them also. I apologise if this offends anyone and I accept in the past people didn't know about such things but to do this now is wrong in my eyes.

I for one would take a dip in breed standards for an increase in health and temperament quality anyday. More international matings would go along way to helping the situation also as the different populations will have had time to diverge (a little at least) in the time they have been apart.

It would be nice to see potential breeders going on courses, not just for genetics but for health issues etc.....this would be in my ideal world  After all puppies aren't going to die from a breeder having too much knowledge!

I do not think the situation, for spaniels, at least, is dire at the moment, we have a large breeding population and nature has a way of 'reshuffling' the genes through recombination of chromosomal locations in the gametes and producting de novo (new) changes in each generation which will help a little.

There are some very good, sensible breeders out there both those that show and those that dont but unfortunately there are also lots of bad or naive breeders who dont know or dont care about these sort of issues. Personally I think that if we capped the price a pup could sell for we would discourge those breeders who are in it for the money and are more likely to use any stud/bitch regardless of their genetic relationship/temperament or health issues.

But then I don't breed dogs this is just the opinion of someone who has studied genetics for 7 years, I realise the practice of it may be quite different.

[Eceni]

Thank you - that's one of the most refreshing posts I've read in a long time.  As a vet, I'm not as fully up on genetics as you are, and am frantically trying to catch up, but am horrified by the breeders (not in the working cockers so much, more in the first breed I looked at) who are adamant that father/daughter, mother/son, brother/sister matings are perfectly normal and in fact constitute good breeding practise.  There's also a common practice of breeding a sire to two related dams  - usually sisters, then taking bitch puppies from both litters and mating them back to their father, then taking a bitch and a dog from the resulting litters and breeding them together.  It's not hard to find pedigrees where this has been done not just once, but several times in a 10 gen pedigree. 

In that particular breed, we're beginning to see auto-immune diseases, but because they're so hard to pin down and there are often many differing environmental factors, it's difficult to prove that they're related to the breeding practice. 

there's a constant tension between 'good genetics' and the ability to breed to type.  I haven't found anyone who has a solution yet - given the entire concept of dog breeds, I'm not sure there is one, but would be interested to find out what ideas are out there.

thank you all for your input

e

[tiamaria]

Thank you - that's one of the most refreshing posts I've read in a long time.  As a vet, I'm not as fully up on genetics as you are, and am frantically trying to catch up, but am horrified by the breeders (not in the working cockers so much, more in the first breed I looked at) who are adamant that father/daughter, mother/son, brother/sister matings are perfectly normal and in fact constitute good breeding practise.  There's also a common practice of breeding a sire to two related dams  - usually sisters, then taking bitch puppies from both litters and mating them back to their father, then taking a bitch and a dog from the resulting litters and breeding them together.  It's not hard to find pedigrees where this has been done not just once, but several times in a 10 gen pedigree. 

 

[Cob-Web]

I have to admit I did not know that some people actually recommend inbreeding of close relatives......while I understand the desire to have consistency in breed standard, breeding a bitch to her grandfather etc is just asking for trouble and in my opinion this sort of partice should be banned. Dogs after all are mammals like us, their DNA is structured the same as ours, made up of the same 4 bases and functions in the same way therefore the laws of inbreeding (for planned litters anyway) should apply to them also.

Of course, the main reason that humans do not closely "line breed" is because it is socially unacceptable 

If you consider wild "pack" animals, then their social organisation requires either the male or the females to "transfer" from one pack to another when they become sexually mature, to prevent close inbreeding -  but within these natural, dynamic hierarchical structures, the "co-efficient of inbreeding" is still far higher than western humans would consider socially acceptable in their own species     

Consider a pack species where the males *transfer* when they become sexually mature - this prevents them mating with their siblings and half-siblings - but once established within a new pack, they will sire offspring with the females, and may well mate with their own female offspring some years later 

Of course, close inbreeding over many generations is genetically undesirable for many reasons, and is naturally selected against in the wild - but many of the "laws" that apply to humans (particularly in Western society) are based on social pressures that have developed as a result of the horror felt towards babies (born to close relatives) which are suffering from conditions that could well have been coincidental, or at most, statistically unlikely 

[Eceni]

Of course, the main reason that humans do not closely "line breed" is because it is socially unacceptable 

If you consider wild "pack" animals, then their social organisation requires either the male or the females to "transfer" from one pack to another when they become sexually mature, to prevent close inbreeding -  but within these natural, dynamic hierarchical structures, the "co-efficient of inbreeding" is still far higher than western humans would consider socially acceptable in their own species     

Consider a pack species where the males *transfer* when they become sexually mature - this prevents them mating with their siblings and half-siblings - but once established within a new pack, they will sire offspring with the females, and may well mate with their own female offspring some years later 

Of course, close inbreeding over many generations is genetically undesirable for many reasons, and is naturally selected against in the wild - but many of the "laws" that apply to humans (particularly in Western society) are based on social pressures that have developed as a result of the horror felt towards babies (born to close relatives) which are suffering from conditions that could well have been coincidental, or at most, statistically unlikely 

Roslyn will have more data on this, but line breeding doesn't happen in people because it's catastrophic in very few generations.  The Amish are having huge problems and according to a friend of mine who's an ophthalmologist, they're beginning to see ocular catastrophes in some of our immigrant cultures where cousins are marrying for lack of more 'outside' blood. It's socially unacceptable because people down the generations for thousands of years have realised it's immensely detrimental to the children.

and my understanding of pack dynamics is such that, unless humans restrict the environment, or a small number of individuals becomes cut off by geography (such as landing on an island where there are very few others) there is almost no inbreeding at all. If you have data to the contrary, I'd be very interested. 

the point with all wild-type inbreeding when it occurs (which is rarely) is that nature exerts a particularly efficient culling system and there's always a danger of wipe-out if the genetically uniform population that results is afflicted by an external pathogen or influence to which they have no defense.

m

[Cob-Web]

and my understanding of pack dynamics is such that, unless humans restrict the environment, or a small number of individuals becomes cut off by geography (such as landing on an island where there are very few others) there is almost no inbreeding at all. If you have data to the contrary, I'd be very interested. 

Robert Sapolsky has spent his life studying Baboons in the wild; his observations (which I confess I have not read in depth) indicate that even this successful and unthreatened species do naturally inbreed to an extent that does not threaten their long term survival 


TBH, I think too much emphasis is placed on the risks associated with inbreeding when you consider that all domestic animals of all species are the result of selective inbreeding - and accidental sibling matings were commonplace between domestic pets even a generation or two ago