Exclusively Setters

Home for Irish Setter Lovers Around the World

We've been having some fascinating discussions on the two previous forum posts 'Animal Protection' started by Henk and 'Advice on Bloat' started by myself.
There has been loads of excellent input and we've pretty well exhausted the subject. I think the general feeling is that once scientists have found the DNA-tests for Bloat, Epilepsy and other genetic illnesses, the Irish Setter will be a healthier breed. The impression is that providing breeders do all the available health tests the breed can continue to go from strength to strength.
I would like to extend the discussion to 'what comes next' - when we have DNA tests.
Are all problems solved? Does it suffice to find the Carriers, breed them to Clears and from then on select only Clears to carry on the breeding programm? Or do we choose outbreeding all the time in the hope the problem will disappear?

interesting links: Canine Diversity website

Views: 154

Attachments:

Reply to This

Replies to This Discussion

Margaret, I hope you don't mind my quoting from your excellent reply under 'Animal Protection'. You wrote:
Mandatory testing doesnt have to be tied to removing carriers and affected dogs from the gene pool. Nobody in their right minds is going to breed from two carriers anyway. As long as breeders have tested their dogs and know the status of the dogs they are breeding , there is no need to remove carriers for recessive gene conditions from the gene pool. Removing too many carriers only narrows the gene pool still further

And finally testing is no substitute for better breeding practices. As long as breeders continue line breeding and using popular sires, DHA and other testing will do nothing more than clean up the problems caused by line breeding and popular sires and small gene pools, and more new problems will continue to show up. So more new tests, Breeders will be running faster and faster in smaller and smaller circles
to do yet more testing just to stay on top of new problems.


IMHO we need to use all the tools we have, including outcrossing to unrelated lines, to assure the health and longevity of our breed. Of course it makes no sense mating one line with a knwon problem to the other unrelated line with the same problem... we can not expect an outcross to solve all problems. But removing carriers from breeding stock too soon - as was probably done in the case of CLAD carriers - will further reduce genetic diversity. We may eliminate one disease by eliminating carriers, but we will soon run into another if we continue with present day breeding practice of inbreeding, as all indiviudals carry unknown 'bad' genes.
Present day purebred dogs need genetic diversity. Health problems are not limited to simple recessive problem traits. Homogeneity not only affects lifespan and leads to inbreeding depression but also affects what is termed the MHC major histocompatibility complex. From what I have read, these genes are responsible for knowing 'self' from 'foreign'. They are responsible for recognizing pathogens like infections, possibly cancer, and lack of heterogenity is suspected to have an influence on immune mediated disorders.
Thanks Susan for the links and the document. I haven't read through all of it yet!!

In other forums recently there has been a lot of discussion about “hybrid IRS” and “opening of registries” “lowering COI” etc and I think these are all aspects of the whole plan as we move forward towards and beyond DNA testing. I don’t believe that DNA testing will be the answer to everything and is probably some distance away. In the meantime, should we start planning prior to the identification and implementation of a DNA test. I guess we should ask ourselves - are we happy with the planning we have in place at the moment?
Some questions that I have relate to some of the other discussions, but equally relate to planning ahead:

Stud Books/Closed Registries
- Are all purebred IS (whether full field lines or show lines) entered in the register of their respective Country of birth? I expect this is yes? (if the Breeder has an obligation to register all litters (and all pups from the litter) bred from their respective kennels as it is in Australia). If so, any progeny from these matings can be entered into the register of the litters’ country of birth? If this is correct, why would there be any need to “open registers” when there is a good gene pool (according to comments in other discussions);

- If the registries were opened and dogs without full pedigrees were able to be assessed and put on the register, this doesn’t guarantee that breeders will use these dogs! if not this will do anything to assist in gene pool diversity?

- Should the limited registers (and forgive me if this is not the case in all countries – Australia has a register where dogs from a litter can be placed if the breeder determines they are not to be bred from) be assessed and extensive consultation to occur with breeders in respect of why dogs are on such registers in the first place and if possible, these dogs can be placed on the full register? Would this increase the gene pool or just increase the number of dogs with the same pedigrees available in other areas of the country?

Breed Planning and Practices
Breed Plans and Practices should already be in place, however, may need to be reviewed given the health problems now facing our breed. even before DNA testing provides some decision support or do we all stop breeding and wait for the DNA test! Our dogs get too old and generations are lost!!

At the moment, we are “flying blind” in respect of some of the health issues facing us and as already said if we remove every dog out of a breeding plan who has ever been “labeled” as responsible for passing forward a “bad trait” or a “health” problem, then we quickly realize we have limited opportunities for breed mate selection. But, it is a big gamble to choose the right ones to take out of the selection process!!

So, what can we do?
1. We remove dogs from the selection process, because we believe there are health problems in the lineage, in the short term. If the DNA test is developed, we can always bring them back in, if they are found not to carry “bad genes” providing this doesn’t take too many years and the dogs in question haven’t all gone to Rainbow Bridge! Perhaps having “semen” collections taken, so this would also be an option in the event that they were cleared!

2. Outcross to unrelated lines with dog and bitch having the desirable traits and good combination of strengths – should minimize loss of type and lower COI (requires extensive knowledge of pedigrees and COR of dogs in lineage). According to the discussions we have already had that there is a good gene pool available, especially between UK and Europe. this should be achievable. Does everyone think this is the way forward? I have my doubts that outcrossing every generation would be optimal. As a breeder we should be consistent with our selection criteria, and this may not always be achievable with outcrossing every litter.

Recent information that I obtained regarding this:
The count in the inbreeding report is “The number of times the individual shows in the pedigree. Higher the count, the higher the possibility of locking in traits from this ancestor.
Keep in mind
While this number can be quite large and the genes are found in the dogs we are breeding, it is more important to look at the COR numbers to determine the true genetic influence. The dog (used in the example) first appears in the 7th generation, and his genes have been filtered through his offspring to our current breeding pair. It is the genes being held by the dogs in the first 4 generations and their immediate relatives that are more likely to be of worry.”


3. Should there be a register, held by the breed clubs (or Regulatory Body) of all the dogs available at stud (which includes any semen also available) to allow breeders access to the pedigree, health tests, etc of the dogs. This also requires public access for overseas breeders.

4. Regulatory Bodies:
- Implementation of Code of Ethics for Breeders/Stud Dog Owners which includes disclosure of health issues of dogs in the pedigree.
- Mandatory testing for CLAD; PRA and HD; and any further testing which becomes available in the future;
- Training/courses for breeders/Stud Dog Owners on genetics, etc. This should occur when a new breeder request a Prefix/Affix, etc or should be implemented and undertaken by all at the point of implementation by the Regulatory Body
- Liaison with the Veterinary Boards to implement mandatory reporting of dogs who have been treated for health issues ie: GDV; Entropian; Ectropian, etc. This reporting would then be placed on the register.
- Implementation of database with all details of all registered dogs and health test results;

A number of these options rely heavily on open and honest communication between breeders/stud dog owners with frank discussion on health issues within the pedigrees. There is no place here for innuendo and unsubstantiated comments. We need the facts!

Mandatory requirements via breed clubs and regulatory bodies need to be put into place to underpin the processes. There are some countries which probably already have some of these requirements in place?

Are these options achievable prior to DNA testing and beyond to improve the future health and longevity of our breed? I believe they are!

Do we want to make the changes and if so, how do we start?
A simple 'solution', theoretically easily put into effect, practically more likely impossible:

Limit use of a stud dog to 2-3 litters as a youngster, then wait until his progeny are 4-5 years old before further litters are bred.

Limit the number of times a stud dog can be used in his entire life, thereby avoiding another bottleneck in the breed.

Another excellent way to promote health and longevity is to breed from stud dogs aged over 8 years.

Bitches could be bred from first time between 2-3 years, observe progeny developement before breeding her again 2 - 3 years later.

And endeavour to plan matings with a COI of below 10 over 10 generations (as suggested by Dr. John Armstrong)
One needs to do both, using DNA tests judiciously without discarding too many dogs, AND trying to reduce COIs , which doesnt necessarily mean outcrossing all the time. It can be done by avoiding very close matings while still line breeding , but doing an outcross at least one generation in three or four

A terrier breeder on a genetics list raised an interesting problem recently. He is a very careful breeder ansd uses all available testing for his breed, and has done for several generations, and now has what is probably the most disease free line in his breed. He knows that in theory he should also be outcrossing to reduce COIs but is finding that he can now only outcross to lines who carry more problems than his own . What does he do? Continue to line breed on his healthy stock knowing that long term he will still run into problems like decreasing litter size and poorly functioning immune systems and possibly recessive gene problems that havent shown up yet in his breeding? Or does he outcross , taking the risk of new problems getting into his breeding, while gaining the benefits of heterosis?

Interesting question
A few interesting questions:

What if Bloat is poly-genetic? Do you risk deselecting for multiple genes at the risk of unwittingly selecting for something else, also carried on those genes? Let's not forget that many diseases are caused by the presence of homozygous recessive pairings...so deselecting can cause problems as well as suppress them. (Eg carrier to carrier = 25% chance of recessive trait showing up.)

What if the gene for Bloat happens to also be the gene that carries the red hair? Are we happy for Irish Setters not to be red any more, providing they don't carry Bloat? (Okay, maybe a far-fetched question, but not impossible...especially if you look at the astounding results produced by Dimitri Belyaev when he was selecting ONLY for tameness amongst his foxes. And he wasn't even trying for a specific physical trait.)

It just concerns me that we expect all our problems to be solved by genetics. It is no different, IMHO, to selecting for (eg) longer backs...then accidentally "creating" HD in the dog as a consequence of the altered skeleton. I am no expert in genetics, but I am fairly certain that deselecting any gene in favour of another carries just as much uncertainty long-term as not. To put it plainly: Any time you mess with something you don't fully understand, you might get more than you bargained for. Even if you don't realise straight away.

I am in favour of genetic testing, btw. But I do take it all with a grain of scientific salt.
Our breed is associated with success of PRA testing.

The inventor of the testing-scheme, Rasbridge, warned that breeders were “spoilt” because of that (source: Ierse setters in mijn tijd, Ierse Setter Club 1915-1980). Contrary to PRA, he warned, genetic explanations of quite a few other defects were not available. As well he pointed at the dive down in number of bloodlines.

Thirty years later, more defects in his list like epilepsy are still without clear genetic explanations. And bloat was missing in that list, meanwhile one of the biggest problems. The number of bloodlines has further declined in the UK and UK-influenced circles.

This documents DNA-testing is not enough. Search for non or not so much related families in the breed, forget about a competition based selection system only, try to breed litters that live long and happy, only visiting vets for inoculations.

In a nutshell: back to basics.
I think it is difficult to make any assumptions on what traits may be at risk if/when we get a DNA test for bloat until the scientists can actually pinpoint the gene/s which may be responsible for it.

Given what Melinda has said, could we contribute any of the health problems we have now to the removal of dogs who carried CLAD and PRA or suffered from HD from the gene pool as breeders have continued the practice to increase COI which may have increased the presence of homozygous recessive pairings?

I don’t get the impression that anyone thinks that a DNA test will solve all the problems. I see it as a tool which can be used to assist breeders to make informed and wise decisions to improve the health of our litters.

If DNA testing does identify that there is a genetic link to bloat and there are certain lines that carry this gene, then it provides breeders with the information and they are able to make their decisions as to whether they exclude and/or diligently select the best options for breeding pairs. Without a conclusion as to whether bloat is genetic or not, we are making decisions on breed mate selection with what little information we have, whether it's correct or not.

For example, given some of the information filtering through relating to pedigrees/lines which appear to be more affected than others, and if we jump to a conclusion, from what little information we have, we may be excluding dogs from the gene pool that we don’t need to!!! Aside from that, there are a good number of lines still out there in the world to choose from who carry all the traits that we would want which do not seem to be affected with bloat.

Again, (I know I’m being a cracked record here!!!) this process is only possible by all breeders and stud dog owners being very honest and frank about the health of their lines and I think this is part of the real dilemma for breeders who may want to use unrelated lines, but don’t know what other problems they may bring in!!

I think we need to have a balanced view. Even if we exclude a known bloat carrier, we still have to have a breeding program with a selection criteria of what traits are important. If we choose a specific trait over everything else whether we have DNA testing or not, we risk the loss of other very important traits. Moving forward by lowering COI to breed out health problems is an essential part of the breed mate selection together with the selection criteria we already utilise today.
Melinda, you wrote: To put it plainly: Any time you mess with something you don't fully understand, you might get more than you bargained for. Even if you don't realise straight away.

I'd say that goes for most things in life: The moment we realize things are not as simple as we thought, that is when we realize how little we actually know... but to me, that is the beginning of a learning curve.

If we transfer your phrase to dog breeding, then we could to say that over the past 100 years that is what breeders have been doing: selecting by inbreeding without fulling understanding the outcome. No offence meant, science has come a long way since so we can not point fingers at people in the past for doing anything wrong. In those days it was thought that it really WAS possible to throw out the bad whilst retaining the good... Genetics were simply either dominant or recessive and it was thought a single gene was responsible for each trait. We now know that 'the bad' comes along with the good, no living creature has only perfect genes.

I maintain that breeders should aim at breeding dogs that are healthy and longlived - and only when that is achieved can we select for further atributes as working or/and show qualities. In research done in Standard Poodles it was shown that a dog with a 10 gen COI of only 5% will on average live 3 years longer than one with a COI of 35%. I wonder what the outcome would be if this kind of research was done on Irish Setters?
Article on the uses and limitations of DNA testing in the December issue of K9 magazine
Attachments:
Excellent article! Thank you for sharing.
Am I wrong in thinking the KC will not register CLAD or PRA carriers? This in itself will limit the available genepool, as by using a carrier to a clear the status of the litter can be determined by DNA testing. KC registration has the added bonus of knowing the carrier dogs are in an "official" recognition of their place in a breeding programme. This is important I think.

In NZ not all Irish breeding stock is clear of CLAD and/or PRA - some people simply breed to a tested/clear by descent dog without knowing the status of their bitches. I think they feel that the further back in a pedigree the "problem" lies, eventually the gene will "die out" (as one breeder said to me - sigh!).

Unfortunately, genes do not work in this convenient manner. Education must play a part but given human nature, it is only the KC ruling that sorted out the dogs in the UK. It appears that mandatory regulation is required to actually push breeders into doing something. Our NZKC will not register the results of DNA tests against the dog - I have been trying for years to get mine registered against my dogs. They put HD results on - I can't see the difference myself.

DNA tests are a tool, but NOT the only tool. But they are better than nothing.
hi pat i am unsure of the answer to your first question. there did used to be a register on the kc site of dogs that had been tested clear or who were carriers or who were affected.now i think theres just the clears published.
im not into the breeding side of dogs as the previous 2 bitches i owned i didnt want them to have any. layla we was going to breed from until she was diagnosed with pra. this is now not to be. she was diagnosed as having late onset pra at 2 and 1/2 years old (the proffessor said shed probably had some 18 months before diagnosis).she is totally blind now at 5 years old.
after diagnosis we had her dna d and it came back clear from the rcd1 that setters are dna for and " her future puppies would be clear".she was also hereditry clear of pra when she was bred and none of the others in the litter have shown signs of lopra at the moment.
it was by chance that laylas condition was noticed, we went on holiday and with my dog, been in different surroundings that her actions were noticed by my daughter and we quickly had her investigated .
also what worries me is IF we had not know about laylas condition we could have bred from her on the hereditry clear factor .
i would also like to add i had 200% support from my breeder then and now and i think responsible breeders will do anything in their limits not to breed unhealthy dogs.
i agree with you about dna tests not been the only tool in the healthy breeding of dogs

RSS

Badge

Loading…

© 2022   Created by Gene.   Powered by

Badges  |  Report an Issue  |  Terms of Service