Inherited Conditions

[Alyosha]

This is a question mostly for breeders, but as some experienced folk aren't in the Breeders Forum I thought I would put it here.

I'm writing a short article on genetic conditions generally and their implications within pure breeds. I'm hoping to find some simple examples I can include (without naming names or breeds necessarily) of what has occurred as a result of people ignoring genetic conditions within breeds. So examples where it may have suddenly spiralled out of control, had an unforeseen dramatic effect, resulted in big impact on the breed population, cost a bundle for breeders, etc etc.

Am happy for PMs if people are more comfortable.

So any examples springing to mind? Bearing in mind that I am seeking stories of broader breed-based implications rather than individual stories of problems or heartache. I'd love to include those but it has to stay brief and focussed.

[espinay2]

Not dog but a good example Perhaps is the quarter horse 'Impressive' and the genetic mutation that is thought to have spread from him.

[sandgrubber]

I think if you might get more response if you phrased this differently and asked about "learning the hard way" about accepting a dog or bitch with health problems. I have had a few breeders tell me, with no shame, that they will never again use a dog with bad elbow scores because they ended out with a litter where almost all the pups had problems.

[Alyosha]

I think that's part of the bigger problem sandgrubber - that people have a tendency to not accept advice and to only learn from their own mistakes.

It's always a frustrating exercise trying to get people to learn from other's mistakes... But examples can help to personalise a message sometimes and if it just relates to one or two people on a deeper level it's worth it!!

Edited September 23, 2013 by Alyosha

[Diva]

You have me curious as to who is ignoring what, lol.

I think the way Border Collie people worked together to develop a genetic test for one of the diseaes they suffer, I think it was C L, is a great example of how it can go when people don't ignore it, and I think a champion of that was or is on DoL. But the disease was also found in humans so some research money came via that route, if I am not mangling the story. Apologies if I am remembering that wrong. And a couple of breeds have found themselves in trouble by trying to eliminate all carriers of a condition and by that inadvertently concentrating other serious disorders in the remaining gene pool, instead of using carriers sensibly. But not really what you are after I guess.

Edited September 23, 2013 by Diva

[SkySoaringMagpie]

You can know that x line has issues but often there is no peer reviewed scientifically proven means to track it and prove it. So then it becomes a matter of self discipline. Plausible deniability is huge in some breeds.

Edited to add - to ignore a genetic condition you have to know that it exists by way of testing or careful tracking by definition. I think it's going to be a popular sire thing a lot of the time and while I can think of "bad news" stories I can't think of one where the dog was tested or the complete history was known and then a whole community went ahead and used it anyway. At least, I hope there isn't one, once it's out there people tend to steer clear IME.

I can think of situations, before the advent of testing or indeed, in some smaller breeds numerically that don't have genetic tests, where the signs point to something being wrong, but because it can't be proved, or because the signs arrive late in the dogs' lives (eg, beyond the period where they are usually used to pass it on) people have been a bit careless because of the plausible deniability I mention above.

Edited September 23, 2013 by SkySoaringMagpie

[Leah82]

An example of an individual case. Our cocker purchased from a breeder in QLD before genetic testing has PRA. Along with that recessive strain he also got the liver colour strain and he had an undecended testicle. I wonder if getting one recessive strain increases the likely hood of further issues showing up later on, either that or he 's extra special :-)

[*kirty*]

We had a breeder come into our clinic to get testing done on their bitch who had not been tested before. The bitch was already heavily pregnant with the last batch of a very valuable and long deceased dog's semen. We found that the bitch had hereditary cataracts. Not sure what they were planning to do with the pups.

[minimax]

An example of an individual case. Our cocker purchased from a breeder in QLD before genetic testing has PRA. Along with that recessive strain he also got the liver colour strain and he had an undecended testicle. I wonder if getting one recessive strain increases the likely hood of further issues showing up later on, either that or he 's extra special :-)

She specifically asked NOT for individual cases.

[Alyosha]

You have me curious as to who is ignoring what, lol.

I think the way Border Collie people worked together to develop a genetic test for one of the diseaes they suffer, I think it was C L, is a great example of how it can go when people don't ignore it, and I think a champion of that was or is on DoL. But the disease was also found in humans so some research money came via that route, if I am not mangling the story. Apologies if I am remembering that wrong. And a couple of breeds have found themselves in trouble by trying to eliminate all carriers of a condition and by that inadvertently concentrating other serious disorders in the remaining gene pool, instead of using carriers sensibly. But not really what you are after I guess.

No that's really good actually. I think half the issue is that some people worry it will be a huge cull process (sort of like a foot and mouth breakout) and valuable individuals and lines will be completely lost. And I guess some of that comes from past actions like you mention - where elimination attempts have maybe gone overboard.

Leah it's very interesting that your boy has an odd colour as well. I don't know enough about genetics to know whether they are associated by coincidence or something more. Maybe he could be a genetic study all by himself! :)

SSM I agree completely. All food for thought.

Kirty that's another sad story. I presume the pups could have all been tested down the track. If the long dead sire was clear they may have been ok, although some may have been carriers. Depending on it's inheritance pattern of course.

[SkySoaringMagpie]

You have me curious as to who is ignoring what, lol.

I think the way Border Collie people worked together to develop a genetic test for one of the diseaes they suffer, I think it was C L, is a great example of how it can go when people don't ignore it, and I think a champion of that was or is on DoL. But the disease was also found in humans so some research money came via that route, if I am not mangling the story. Apologies if I am remembering that wrong. And a couple of breeds have found themselves in trouble by trying to eliminate all carriers of a condition and by that inadvertently concentrating other serious disorders in the remaining gene pool, instead of using carriers sensibly. But not really what you are after I guess.

No that's really good actually. I think half the issue is that some people worry it will be a huge cull process (sort of like a foot and mouth breakout) and valuable individuals and lines will be completely lost. And I guess some of that comes from past actions like you mention - where elimination attempts have maybe gone overboard.

I really, really, REALLY want to hear Dr Kate Meurs speak sometime. Someone in my breed pointed me to this conference abstract which points out that genetics is only one part of the puzzle for hearts and that even if you toss out everything that is known to be genetically suspect, you still don't fix the problem. Of course, balanced breeding requires some collective maturity on the part of the breed community.

Inherited Cardiomyopathies: Kathryn Meurs, North Carolina State University

Cardiomyopathies are diseases of the heart muscle. The two most common types are Dilated and Arrhythmogenic, which together occur second only to valvular disease in dogs. Arrhymogenic Right Ventricular Cardiomyopathy (ARVC) is common to Boxers and to a lesser extent, Bulldogs. The heart muscle contracts well but microscopically, many of the muscle cells die and are replaced with fat cells, leading to abnormal electrical conduction. Affected dogs have an abnormal heart beat that may cause them to faint or die suddenly. A genetic mutation has been found in a region of the genome involved in making a protein that sticks cardiac cells together. It seems to be inherited as an autosomal dominant; however, dogs with two copies of the mutation have more abnormal beats per day than with one copy. Usually. Actually, the mutation has about 72% penetrance, meaning that 72% of dogs with the gene will have disease, but 28% of dogs with the same gene will not.

Dilated cardiomyopathy (DCM) is most known in the Doberman Pinscher, but also occurs in many large breeds. However, it may be different kinds of DCM in different breeds. In humans, 24 different genetic mutations can cause DCM. In Dobes, the cardiac mitochondria, which is involved in cell metabolism, is abnormal. In at least some families of Dobes, dogs with a mutation in a mitochondrial gene develop DCM. The gene is an autosomal dominant. About 28% of Dobes with this gene develop DCM, suggesting that as with humans, there may be different genetic causes even within one breed.

DCM in Great Danes is again a different form, appearing to be caused by a sex-linked gene. This again suggests that you can't generalize DCM genetic studies between breeds. You have to start fresh: characterize the disease in your breed; characterize familial patterns; and characterize molecular aspects of the disease.

Realize that a gene test may not be as helpful as you hoped, especially in cases where the mutation has incomplete penetrance. Why do some dogs with the mutation show the disease and not others? Is it diet, daily activities, genetic background? And if you have an unaffected dog that has the mutation, how do you use that information to guide breeding decisions? Add to that the situation where you may have more than one mutation causing DCM in a breed, and you have another concern: Just because your dog "passes" the one available DNA test for DCM, it doesn't mean he may not carry a different gene for DCM. Meurs suggests dogs must still be phenotypically tested with Holter monitors and cardiac ultrasounds. She does not suggest wide-scale removal of dogs with the mutations, but balanced breeding to dogs not carrying the same mutation.

Edited September 23, 2013 by SkySoaringMagpie

[Rebanne]

You have me curious as to who is ignoring what, lol.

I think the way Border Collie people worked together to develop a genetic test for one of the diseaes they suffer, I think it was C L, is a great example of how it can go when people don't ignore it, and I think a champion of that was or is on DoL. But the disease was also found in humans so some research money came via that route, if I am not mangling the story. Apologies if I am remembering that wrong. And a couple of breeds have found themselves in trouble by trying to eliminate all carriers of a condition and by that inadvertently concentrating other serious disorders in the remaining gene pool, instead of using carriers sensibly. But not really what you are after I guess.

there is a disease in greyhounds, so far only acknowledged in show bred, and possibly only in show bred, that was very quickly found a test for. We were very lucky it was "easily" able to be tracked down. Carriers are still used in breeding programs.

[LisaCC]

What about collie breeds and MDR1? Yes there is a test for it but a lot of people still breed carriers together and even affected dogs.

[mixeduppup]

I'm meeting more and more deaf cattle dogs and coolies of late.

[sandgrubber]

This is a question mostly for breeders, but as some experienced folk aren't in the Breeders Forum I thought I would put it here.

I'm writing a short article on genetic conditions generally and their implications within pure breeds. I'm hoping to find some simple examples I can include (without naming names or breeds necessarily) of what has occurred as a result of people ignoring genetic conditions within breeds. So examples where it may have suddenly spiralled out of control, had an unforeseen dramatic effect, resulted in big impact on the breed population, cost a bundle for breeders, etc etc.

Am happy for PMs if people are more comfortable.

So any examples springing to mind? Bearing in mind that I am seeking stories of broader breed-based implications rather than individual stories of problems or heartache. I'd love to include those but it has to stay brief and focussed.

It may also be worth referencing Dr John Armstrong's work with Standard Poodles, and the importance of the Wycliffe lines. Where a few dogs have dominated breeding, the diseases of those dogs become the diseases of the breed. And high COI's don't help the immune system. See:

http://www.dogenes.com/poodle/poodle.html

[dragonwoman]

I'm meeting more and more deaf cattle dogs and coolies of late.

May be partly due to fact that deaf pups are not usually culled these days

[mixeduppup]

I'm meeting more and more deaf cattle dogs and coolies of late.

May be partly due to fact that deaf pups are not usually culled these days

No, I work at a vet and see people bringing in dogs they use for breeding and quite a few of those need to be tested for BAER in my opinion but people are just ignoring the fact and breeding anyway.

[SkySoaringMagpie]

I'm meeting more and more deaf cattle dogs and coolies of late.

May be partly due to fact that deaf pups are not usually culled these days

No, I work at a vet and see people bringing in dogs they use for breeding and quite a few of those need to be tested for BAER in my opinion but people are just ignoring the fact and breeding anyway.

How is that inconsistent with what dragonwoman wrote?

[mixeduppup]

I'm meeting more and more deaf cattle dogs and coolies of late.

May be partly due to fact that deaf pups are not usually culled these days

No, I work at a vet and see people bringing in dogs they use for breeding and quite a few of those need to be tested for BAER in my opinion but people are just ignoring the fact and breeding anyway.

How is that inconsistent with what dragonwoman wrote?

I understood her post as saying that people are bringing in deaf puppies as pets. I'm very one dimensional in my understanding today. I guess she's right.

[Guest Maeby Fünke]

What about Pugs and Mast Cell Tumours?

I know of so many people whose Pugs have/have had Mast Cell Tumours, and the oncologists have told me that Pugs are "prone to them" as a breed, yet no vet or breeder prepared me for them. I find that really strange and I wonder if there are some conditions that are considered taboo and are not talked about within a breed community.

The general impression I get from other Pug owners (whose Pugs have/have had MCT's) is that the owners are not educated or informed about Mast Cell Tumours and they are in the dark about how to deal with them. I also get the impression that Pug owners are more or less on their own in dealing with Mast Cell Tumours with little support from the Pug community.

I wonder whose role it should be to educate Pug owners about Mast Cell Tumours, ie. vets, breeders, Pug clubs or the owners themselves. I don't mean to sound arrogant, but I have very high standards as a pet owner and I can't imagine the general public going to the same trouble that I did to educate myself about MCT's.

Also, if MCT's are an inherited condition, like PRA in Labradors for example, then why don't the Pug clubs declare them as such? Actually, I'm guessing that this is because the mechanism of inheritance with MCT's is not yet fully understood and so there isn't a test yet that is available.

eta

Sorry, I edited my post because I realised I had a bit more to say :)

Edited September 24, 2013 by Maeby Fünke