Ok, so who on this board thinks that TVD is hereditary or could it be congenital, meaning an isolated defect not related to genetics??????

Just looking for some opinions....

I'll tell you my opinion after later....

I do not have an opinion that I wish to express at this time, but I do have a web site that might be useful for people to read http://www.vetsforum.com/article_tricuspid_valve_dysplasia.htm

And this is interesting as well.
Abstract
American Journal of Veterinary Research
June 2002, Vol. 63, No. 6, Pages 816-820
doi: 10.2460/ajvr.2002.63.816

Evaluation of the genetic basis of tricuspid valve dysplasia in Labrador Retrievers

Thomas R. Famula, PhDLori M. Siemens, DVMAutumn P. Davidson, DVMMartin Packard, PhD
Department of Animal Science, College of Agricultural and Environmental Sciences, University of California, Davis, CA 95616. (Famula); Sacramento Veterinary Surgical Services, 9700 Business Park Dr, Ste 404, Sacramento, CA 95827. (Siemens); Guide Dogs for the Blind Inc, 350 Los Ranchitos Rd, San Rafael, CA 94903. (Davidson); Institute for Genetic Disease Control, PO Box 222, Davis, CA 95617. (Packard)

Objective—To quantify inheritance of tricuspid valve dysplasia (TVD) in a population of Labrador Retrievers and evaluate the possibility of the effect of a major locus on TVD.

Animals—521 Labrador Retrievers (345 with known phenotypes and 176 related dogs with unknown phenotypes).

Procedure—Dogs were considered normal, equivocal, and affected for TVD on the basis of echocardiographic appearance of the tricuspid valves. Information on related dogs was collected for estimation of heritability of the 3 categories of phenotype, using a threshold model. Complex segregation analysis was performed to evaluate the possibility of the effect of a major locus on TVD.

Results—Heritability of TVD in this population of dogs was found to be 0.71, a value sufficiently large to suggest a segregating major locus. Subsequent complex segregation analysis did not provide sufficiently strong evidence to indicate influence of a major locus on the prevalence of TVD. However, complex segregation analysis for 2 categories of phenotype (eg, equivocal dogs were grouped with affected dogs) suggested that there was a single recessive allele with a substantial impact on the expression of TVD.

Conclusion and Clinical Relevance—In Labrador Retrievers, TVD is a heritable disorder. Affected dogs and dogs closely related to affected dogs should not be used for breeding. There was insufficient evidence to suggest the influence of a major locus on TVD, although this conclusion was affected by the classification of dogs for diagnosis of the condition. (Am J Vet Res 2002;63:816–820)

Thank you! Even if you are unwilling to share an opinion, this article is very helpful.
However, if no one is willing to talk about it, how are we ever going to get rid of it???

This quote is taken directly from the mentioned link:

"The genetic etiology of TVD in dogs has been recently located to a defective gene on chromosome 9 and is a heritable disorder."

Don't know. I wonder if some of the diseases we've been discussing are linked to one another. Could EIC be related to TVD, or another heart issue?

And again we get back to what Lisa was saying. The statement re: TVD by Lori Seimans ( probably spelled wrong but you know whoI mean) that dogs closely related to dogs who have or have produced TVD should not be bred is exactly what we all used to do about PRA. So think about that....Receiver produced some PRA, so what if Ruffy had been neutered, or if he had been bred and then his son Arnold had been neutered. We would have lost two extremely valuable dogs to the breed and neither were affected or carriers. Our Strutts as it turned out was a carrier and thank God for Optigen because they came along just about the time we learned that he was a carrier, and we were able to test his brothers and sisters and ended up with several siblings that were A's and we were able to find out his sire was not a carrier and learned his mother was in fact a carrier but not affected. This went on all over the world- many valuable lines were saved by this test. And we learned a valuable lesson. If there had been no optigen test, you have to know a lot of people would have blamed Brodie just because he was the 'stud dog' that sired Strutts who was a PRA carrier, and yet, it turned out to be his mom. So assuming that all relatives are carriers is just counter productive to the breed. Are we going to make mistakes by breeding blindly without absolute knowledge of the genetic makeup of these dogs- of course but until we have more dna tests for more disease in canines, it is all we can do.
Judy

Very good statement Judy. I so appreciate your valuable information and knowledge. You are a class act!
I do have a question to you though - not sure how to ask this w/o becoming offensive so I'll just ask.
In your opinion, since there is no genetic marker yet for TVD - should the parents of a TVD offspring continue be bred? How about littermates of the TVD puppy? Even further, how about if your own research has traced back where it may have come from? Should those lines continue to produce?
I'm not even sure if there is an answer to this myself. It's a tough one.
For me, I'd rather have a blind dog than a dog in CHF from TVD or a dog that drops dead at a year of age.
I think TVD is far more serious and that's my opinion only, others may not share it and thats fine.

Does anyone know if anything is being done currently to study TVD in Labrador Retrievers?

We have a ten year-old dog that has a moderate to severe case of TVD. We found this out when he was 7 months old, as we prepared for a pre-lim x-ray. Needless to say, we were devastated. It came out of no where. We neutered him and did a heart clearance on his sister. We bred her and cleared her first litter. We never had a problem with any of her offspring - she had about 12 puppies total. I try to stay clear of any closely related dogs to ones that are affected, but I think it would have been wrong to throw her out of our program. I am not minimizing TVD, but our boy has had a very normal life and retrieves and swims with the rest of them. Maybe we have just been lucky, but thankfully, he has always been a happy boy and very healthy.

Very interesting ..... Judy I have read and understand that if a particular dog is color dopplered normal/clear they can still pass the gene ?

Is that what you understand too ??

We bred a litter that produced one TVD puppy. (It’s was a bitch puppy that was affected – the dam had never produced a TVD puppy before, or after – from research we believe that it came from the sire side)

We kept a littermate. We bred her 3 times.

None of the puppies where affected. After doing more research, and looking at the pedigrees we accidentally linebred on the supposed source in the first 2 breedings (3 crosses to the supposed dog in the first breeding, and 2 crosses in the second) - All of those pups are over 2 years old. We haven't heard of any problems. We've even kept pups back out of these litters, and never had any problems. They where never bred as they didn't turn out for one reason, or another. We do have a pup out of the last litter that is turning out quite nice. So, maybe we will know more after her first litter (of course this is if she turns out!)

This is just our experience. We’ve had good results when breeding a littermate. Granted this was 7 years ago when heart clearances where just starting, and TVD was just coming out of the woodwork. We where told by our vet, and a cardiologist at the time that it was just a freak thing. So, I don’t know if that helps you at all, but this is one breeder’s experience.

Will we be careful when we bred the puppy that we’ve kept? Yes, but it is not going to prevent us from using her in our program.

Not Judy but yes, I have read that a dog can clear the doppler but still be a carrier. But it also seems from everything I have heard and read that it is a crapshoot. Parents have no signs/are cleared, multiple litters produced, one puppy has TVD. Would be great if they could produce a test....By the way, I still do believe all dogs should be heart tested (not just the studs).

Lets say there were a litter of pups and one pup had TVD but the rest of the littermates were fine. That we know of there had been no TVD in either the sire or dam's lines. Both sire and dam of this pup have had other litters all were fine. My question is, is it possible to have an isolated case of TVD in a pup that was possibly caused by a birth defect in that particular pup?

I have also read that a dog can clear a color doppler and be a carrier. This makes perfect sense to me. It's like a PRA carrier, who is not affected, being able to pass an ERG. ERG - remember them? Before Optigen...

To breeder:

In your scenario were the parents of that puppy echoed, not auscultated, but echocardiographed clear?

I had the situation you're describing happen, however the parents were only auscultated clear. After that puppy was produced the parents were echoed and one did not pass, a second echo was done and confirmed the findings...

I know echo all my dogs in my breeding program and would caution folks not to rely on auscultations only.

Just my 2 cents

I'm assuming you are replying to me:

The sire was (I think just Ausculated), but the bitch was not. The bitch is still alive, and runs around at 12 years old now. I know it's not a doppler, but I do believe we would have seen some problems with her by now. We did a very close linebreeding for this bitch’s first breeding. We had 10 pups - none had heart problems. I would think statistically with that first linebreeding if she was a carrier it should have shown up (i.e was in her genetic background). Again, not an Echo, but we should have seen something.

We've only had the one TVD puppy to date. On the other hand I've heard of other breeders have multiple puppies in a litter be affected

If it is truly heritable, as the experts say, then IMO, no.
Like someone else said, it's a crap shoot and maybe that particular gene is only activated once out of every 25 chances for it to appear? Maybe more.
Whose to say? We don't have a marker.
I have always been under the impression that if it's genetic, it's genetic. This would mean it didn't just crop up by accident, it was hidden somewhere in the genes and something brought it out. Period.
I think this is where our research comes into an important role instead of putting on our blinders and denying our lines could carry such a horrid issue. Chalking it up to a freak thing that wasn't written in the DNA - that's just making excuses and our breed will suffer because of those kinds of attitudes.
I certainly would want to know if one of my boys produced a problem, any problem, and would expect to be told about it. I would then research it to death and try to figure out where it could have come down from.
If I found a traceable source with an obvious connection, which is easier said than done due to the wall of silence amongst many breeders, I would certainly use that education wisely. Maybe it would mean retiring him, maybe it wouldn't. But one thing I could not do is deny/ignore it or call it a freak thing...

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Replying to:

Lets say there were a litter of pups and one pup had TVD but the rest of the littermates were fine. That we know of there had been no TVD in either the sire or dam's lines. Both sire and dam of this pup have had other litters all were fine. My question is, is it possible to have an isolated case of TVD in a pup that was possibly caused by a birth defect in that particular pup?

There can also be heart murmurs that aren't TVD. It takes a specialist and a color doppler to know the different. (This came from a vet school, cardiology dept)

Yes, that is what a Cardiologist told me.

I applaud those who are screening for TVD.

That being said, what other steps should we be taking to get a handle on this?

Does anyone know what happened to the research started by Kathy Wright, DVM? An article on the Woodhaven site said that supposedly Dr. Wright found a chromosome "housing the gene", and that "isolating the specific gene in that region of CFA 9 is the next step,". "Once that is accomplished, a DNA test can be developed for that genetic mutation."

Has anyone approached the LRC or the AKC Canine Foundation, or the NLRC to see if they would be willing to sponsor more research? Make it a priority?

I did speak to Meg Sleeper at Penn a few months ago and she said that a medical genetics group there was finalizing a TVD study but funding was an issue.

Pretty scary issue, IMO.

I understood that Cornell was at one time doing a study, however I don't know what became of it.
It certainly would be great if like Susan suggested, the LRC, AKC or CHIC could help fund one of these studies so we could get something done on this issue!

A lot of questions have been asked in this thread and are unanswered and I certainly do not have the answer. I really have had very little experience with TVD but I think even if I had, I still would know little because the Vet. Cardiologists cannot even agree. What is equivocal???? They cannot agree. Should equivocal be bred?? Is some slight regurgence normal as it is in Goldens???? Again they cannot agree. More research needs to be done with a final answer, but even if one cardiolgist tells you what he/she feels is gospel, it may not be and future research will prove that. When Laurie Semeins first started testing dogs, there were a lot that she called affected and some she retested 7 and 8 years later and passed but that is because of research and being able to see hundreds of Labrador hearts she had more information on which to make her judgements. However there were dogs that were thrown out with that proverbial bathwater long before that day came.
Also to the person who said they got tvd and upon researching the pedigree felt they had doubled up on the dog that was probably the culprit...there are a lot of rumours going around about dogs having had tvd that are not necessarily based in truth, so before you feel comfortable that is the part of the pedigree to avoid, do even more research and be certain.
Judy

I had a bitch that had a litter with two effected puppies. My Bitch and the Sire where both tested with Doppler and They do NOT have tvd. I never did that same breeding but i have bred her with other males and it has never showed up again. One thing I did different with the effected litter was the once a year shot for heart worm which is now gone. The heart Dr. said it could have very well been the problem but we will never know since others don't talk about it and most were not checking for it at the time, and the heart worm shot is not being used any more. Out of the puppies that i have placed from the bitch that produced the tvd puppies I have kept two females that I will use to breed with. I will take in the litters and have them checked at 8 weeks like I have with the others. I wish I knew for sure the answers to the tvd questions. If One of these bitches I have kept from the bitch that produced the TVD has a litter with an effects puppy I will spay them.

-------- Original Message --------
Subject: Re: we want to DO SOMETHING!
Date: Wed, 08 Aug 2007 14:15:18 -0400
From: Meg Sleeper
To: Rebecca Montgomery Bailey
CC: henthorn@vet.upenn.edu;, pwerner@vet.upenn.edu
References: <46B9F862.4020908@bellsouth.net>


Hi Rebecca,
That is great news!! We are definitely interested in proceeding with TVD research, but funding has been the limiting force (as usual). We will put together a plan for the research and a budget to forward to you so that you can determine if it is realistic. One of our group is currently away, so it may require a few weeks to get everything together. Thanks!!!
m

At 01:07 PM 8/8/2007, you wrote:
> Hello Meg, I am writing to offer help with funding any research you have planned, or WILL PLAN
> that is related to TVD, specifically in Labrador Retrievers. As you can see, Susan Lazarchick sent
> me your information in hopes that we, The National Labrador Retriever Club can be of service. If
> you could give us a plan with monetary goals included we want to start some fundraisers and also
> include this research in our "Gift" program that we use our annual dues to fund.
>
> I hope you can help us, and that we can help you. Please let me know any ideas you may have.
>
> Sincerely,
>
> Rebecca Bailey
> Orlando, FL
> 407 281 9481
> Vice President
> www.NationalLabradorRetrieverClub.com
> **********************************************************

you said...."I certainly would want to know if one of my boys produced a problem, any problem, and would expect to be told about it. I would then research it to death and try to figure out where it could have come down from.
If I found a traceable source with an obvious connection, which is easier said than done due to the wall of silence amongst many breeders, I would certainly use that education wisely. Maybe it would mean retiring him, maybe it wouldn't. But one thing I could not do is deny/ignore it or call it a freak thing..."

This is my question to you.....If your male produced a TVD puppy, how would you know where is came from?? There is NO way to tell right now. There is no way your going to find out from researching. There will always be a questions as to what if. Everything is not black and white or people would be doing a spay or neuter.

Rebecca and Susan,
THANK YOU SO MUCH for taking the first step in "doing something"!!!!!!!!!!!!!!!
Now this is what it's all about!
I had hoped my OP would spark some interest/concern and it seems it has worked! I will do anything I can to help this cause as it does hit close to home for me, having produced a TVD puppy last year myself.

For me, it's one of those things I will not mess around with. Until I know more, I will not mess with that pedigree again and have nothing from it now. Thankfully, it was not a well known pedigree, more popular pedigree and nothing in my kennel is related. It was a total outcross.

Thats my personal decision but I also respect others decisions as well, even if they are different than mine.

I do share in the wish that we could all be honest with one another so that everyone can make their own educated decisions regarding breeding to a line, or not.

One small step at a time!

My response to that is, yes, you are very right in that it's impossible to know for 100% sure.
However, with enough persistance and the right connections, one can come to conclusions based on other long time, knowledgable breeders experiences.

I did my research, contacted other breeders with similar lines, even found ones that had produced TVD themselves!
And how did I know this? Becuae those breeders were forthcoming and HONEST about it in the first place. They did not hide it, which made it easy for me find them, through others "in the know".

It's called networking and it's SO very important IMO.

Did I hit brick walls? YES! Did I give up? Nope.
I was finally able to trace the issue back, with the generous help and knowledge of others, to a common line and specifically, a common dog that was known for throwing TVD. This is many generations back, but the connection is there.
I also was not just looking at the litter pedigree, but the vertical pedigree, which isn't an easy task.

So am I correct? Maybe. Am I wrong? Could be. But like I said, until I know different, and someone presents me with a DNA marker, I will have to go with what I learned on my own.

I think information back to a stud owner to try to correlate trends is what is key. Yes heart clearances are helpful on dogs, but if it is a recessive we all know how that works. If you find a dog routinely producing problems with many girls and bloodlines it would be hard to keep the blinders on. 1 litter with a problem leaves you to wonder about bad cross, toxins exposed to bitc during pregnancy, just bad luck, etc. This would be the way to look at anything from TVD, Epilipsy, HD, ED anything. Look for trends not snapshots.

My girl with TVD is now 3 1/2 years old and doing great.

This was her breeders' 1st litter. Their bitch had elbow, eye, and hip clearances. A heart murmur was heard when seen by her regular vet. This vet told them to go ahead & breed her, there should be no problem. My girl, thankfully, was the only pup in the litter (that I know of) with TVD. Heart murmur heard at 8 week check-up, confirmed by echo at the cardiologist.

Breeders said they were not going to breed this bitch again. Last I heard she may have been accidently bred by her son, my girls littermate they kept.

If only that vet would have recommeded a cardio work up for this bitch. Then again, I wouldn't have my girl if they had decided to not breed her.

I heard from someone who told the stud dog owner and was treated pretty meanly. TVD is something that could destroy a stud dog and if you've invested a lot in him you might not want to know.......

TVD seems to be cropping up more and more, or is it my imagination????

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Replying to:

I think information back to a stud owner to try to correlate trends is what is key. Yes heart clearances are helpful on dogs, but if it is a recessive we all know how that works. If you find a dog routinely producing problems with many girls and bloodlines it would be hard to keep the blinders on. 1 litter with a problem leaves you to wonder about bad cross, toxins exposed to bitc during pregnancy, just bad luck, etc. This would be the way to look at anything from TVD, Epilipsy, HD, ED anything. Look for trends not snapshots.

Oh you mean like being accused of slandering the stud dog and his owners? Even being threatened with legal action???
Hmmph....
I say if you don't want to hear about problems, or have others find out, DON'T ALLOW YOUR BOYS TO BE USED BY OUTSIDE KENNELS! Becuase once you do, you open yourself up to scrutiny...if you can't take the heat, stay out of the fire!!
Just my 2 cents...

"This vet told them to go ahead & breed her, there should be no problem."

"Last I heard she may have been accidently bred by her son, my girls littermate they kept."

I'm sorry, this stuff makes me crazy. First of all, does this "breeder" believe everything she hears, or just what she wants to. If I had a dog with a heart murmer, you bet I would get it checked further before breeding, given the CARDIAC problems in our breed. Did she not know there are cardiac problems in Labrador Retrievers? All veterinarians cannot be expected to know everything, it's just not possible.
Yes, I think it's the breeder's responsibility to be educated and motivated enough to do the right thing.

And to let a breeding happen with a son who may also be a carrier or affected, and the two of them potentially produce severe TVD in the innocent puppies and God knows what else? Come on! In it's severe form, puppies can drop dead from TVD, or live, uncomfortably for a year and then die or be euthanized. I have seen it with my own eyes. This is just irresponsible and this person is hurting the breed and individual dogs.
Can everybody see the committment to the breed and the experience level of the breeders in most of these posts as opposed to stories like this last one? Hope so!

If in fact you produced TVD in a puppy why are you blaming the stud dog, did you have a doppler done on your bitch ? Why couldn't it be in your bitch line? Sometimes we are so ready to blame the stud dog and owner and just wondering if this was a personal thing? I would think that the blame should be with you the breeder of the puppy, if you didn't do your homework then Shame On You!!!
Another question, if in fact you know that the stud produced this problem then did you find the genitic marker for TVD? If you did, please share with all of us! Just because someone says, Oh yes, I heard that that dog threw TVD doesn't make it so!
Just Wondering

I had know idea that TVD was that serious? When did this become a really big thing in the labrador?
I have heard of very few and thank goodness haven't produce it. What makes you think this is something that is really prevelent in the labrador now?
This is news too me! I think we had maybe more of it years ago, but haven't heard that much about it yet!

Nope, not personal at all. In fact at first I was 99% sure it HAD to have come from my bitch (who is not of my breeding BTW) but other breeders/mentors steered me a totally different direction, and that was to the stud dog line.
I didn't come to this conclusion on my own, it was handed to me, practically on a platter...

Here's some interesting facts as well - my litter was the stud dogs 2nd litter. His first litter, multiple puppies died within days of birth. A bad C section was blamed. Ok fine. Maybe....
In my litter, multiple puppies died within days and weeks of birth. Hmmmm.... No cause was determined. I did not post them.
Out of the surviving pups, one is confirmed with TVD, grade III/VI. Pretty severe.
Now if you have multiple, knowlegable breeders examining your pedigree and telling you "this is where it came from" - what would you think?????

So as I said, nothing personal at all. If it was, everyone would know it.
My goal is avoid this issue in the future as best I can and to do that, research needed to be done in an attempt to best understand, without a DNA marker, where this problem may have arrisen from. Wow - talk about a run-on sentence!!
I believe I have found the line it came down from, based on other long time breeders experiences, others may disagree.
Doesn't matter to me in the least. Thats their decision. But for my breeding program, I make the decisions, and only I make the decisions.

Would it make sense to start a database of dogs who are affected by TVD or producing it, similar to that done by Georgia Gooch who published pedigrees of affected labrdors through PRA DATA many years ago?

Probably not, it would probably cause more problems than it fixed, but if we're not going to throw out dogs, it would help to know where there are issues.

?????

Robin -

I totally agree with you.

I couldn't believe when I heard that the bitch was possibly bred by her son. It was this breeder's niece who told me.

The breeder seemed upset about the TVD - they had no idea Labs had heart issues.

I have not had contact with them for a couple of years so don't know if they have continued to breed the bitch. I have been 'afraid' to ask the niece when I have seen her.

I really don't think it is fair to look at a pedigree and say, well this dog threw TVD or whatever and look at this dog in the pedigree, maybe 4 generations back threw TVD. Like Judy said, if we didn't use Reciever, what would we have today? Are these accusations that people make about dogs backed up by scientific proof?
Puppies dying from TVD at birth or a week later is a new one for me?? You say you didn't have the puppies posted, so you are assuming your loss of puppies in the litter is a result of the one puppy being diagnosed with TVD? That is very interesting. Are there any puppies still alive from your litter?
I would think that you would be wanting a doppler done on them to see if there are in fact others in the litter with TVD? Then you can make a real scientific "guess" it was in fact the stud dog.
Do you know if there was a doppler done on the stud dog or have you done one on the bitch (which isn't your breeding)?
I guess I am saying that you are not justifying your sole blame on the stud dog. You say you researched the pedigree's and your mentors said it was the stud dogs pedigree, but not backed up by any proof.
We all make mistakes in dog breeding, but we need to learn and further our knowledge and just not blame one dog, as you must know genetics is wonderful or a terrible thing.
I can understand your wanting more studies on TVD,
I really don't know of allot of it out there, and am sorry for your loss. Just wondering

Yes there are still puppies alive from my litter, including the TVD puppy himself. How long he will live? No one knows but he is in an excellent pet home and yes, he has had a doppler done.

Most of your questions seem to be pretty repetative, so I won't bother defending myself. No reason to because like I said, my breeding decisions are mine alone.
As far as proof, you know as well as I do that there can be no proof until a marker is identified. But until then, I will use my best educated guesses on what and where to breed my dogs.
If and when an active research study is underway, I will be the first in line to voluteer my pedigrees, DNA or whatever they need!
Side note, mysteriously, the stud dog is now "retired" according to his owners website

Informing the stud dog owner of a problem with pups from a litter is not insinuating that he produced it. It takes two. But, the stud do owner needs to know so they can look for trends just as the bitch owner looks for trends. Telling the stud dog owner is not publicly bashing the dog. It can be done discreetly.

Yes no kidding but when the stud dog owner is a newbie with little knowledge of the breed and very few knowledgeable breeder-friends, they don't show and know nothing about pedigrees, they tend to get a bit defensive.
`Ironically with that last sentence, I think I just figured out where I went wrong!! LOL!!`
In my case, the response I got was "didn't come from my dog"...
The stud dog owner did not breed the dog, they bought it and my litter was his 2nd litter, so what kind of a response was that??
An uneducated one.
Then came the threats of lawsuits for "slandering" them...
Ridiculous to say the least!

Am I sitting here blaming the stud dog owners? NO! Absolutely not. I am at 'almost' as much fault for not knowing ahead of time what may lie in these lines. But how could I have?
I don't think anyone is to "blame" here. My point was not to blame, but to point out that denial, hiding facts and breeding blindly causes these types of issues.
So next time someone approaches you with a possible issue that COULD have come down from your lines, don't sit there and close your mind to it - "it couldn't be MY dog"...."MY dog is perfect"....but instead, put on your detective suit and start digging!! You might just surprise yourself!

I wouldn't think my questions are repiditive, you don't have to answer anything. But being judgemental with your conculsions as to how this problem that you produced doesn't make sense?
The stud dog being retired now doesn't show anything.
There could be many reasons why the dog is retired. Have you talked to the owner of the stud dog, are they aware of the fact that you are blaming him for having TVD? You know knowledge is a wonderful thing if it is known. Maybe they want to know more about your conclusions and how you made them.
I can't change your focus of the stud dog being carrier of TVD, that is a your "mind set". But, I would hope in the future that if people are blaming your "stud dog" for something that you will remember your thoughts on this particular stud dog that you are blaming for passing the TVD gene.

If you read all posts, you would see that the owners were informed, and flat out denied any connection.
Oh and yes, I will certainly remember this for the future should any of my dogs be suspected of producing problems.
A good breeder will always be open minded to any concerns in their lines...

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Replying to:

I wouldn't think my questions are repiditive, you don't have to answer anything. But being judgemental with your conculsions as to how this problem that you produced doesn't make sense?
The stud dog being retired now doesn't show anything.
There could be many reasons why the dog is retired. Have you talked to the owner of the stud dog, are they aware of the fact that you are blaming him for having TVD? You know knowledge is a wonderful thing if it is known. Maybe they want to know more about your conclusions and how you made them.
I can't change your focus of the stud dog being carrier of TVD, that is a your "mind set". But, I would hope in the future that if people are blaming your "stud dog" for something that you will remember your thoughts on this particular stud dog that you are blaming for passing the TVD gene.

I don't think anyone mentioned that you were blaming the stud dog owners, you were just making unscientific judgements about the stud dog. You had one puppy that had TVD and lost others in the litter which you never posted, the stud dog sire another litter before that and the puppies died with the c-section you have taken the stance that it is the stud dog that is the carrier. I could see were the owners were on the offensive and not being a show person has nothing to do with there ability to know pedigree's or dogs in pedigree's. That is a very bias opinion!
Unless this is a dominate gene, it takes two to produce this problem or it could be a recessive gene.
I think those are allot accusations you are making, breeding blindly, denial, hiding facts? Or could it be that maybe they just didn't know?

No way am I going to get into a contest of words with you here. I have better things to do and this thread was started to get opinions from other breeders and to hopefully get some interest sparked about continuing the research to establish a mode of inheritance. It was not started to stud dog bash, breeder bash or accuse anyone of anything.
Maybe they didn't know. Fine. I don't really care one way or another. They have been informed and they can do with that what they want.
I think you are double talking here since now you are saying it takes two, and earlier I believe it was suggested that it could have been a "fluke".
Yes, it has already been identified as a recessive gene. So yes, I am very open to the "it takes two" theory. Never said I wasn't!

I believe I clearly stated I was not using EITHER pedigree in my program any longer...
The fact is, I have yet to be able to trace the bitches pedigree to a line known to produce TVD. The sire's I have. Period.
So instead of turning this into a "let's defend the stud dog owner" thread, why not DO something about the TVD research. They lack in funding.
So help them out...prove me wrong, or right!!

No words, just stating facts that were not presented!

That is wonderful to hear that you aren't using either of these dogs in your breeding program.
I think you are getting two threads mixed up when you are saying there is a contradiction in things said, there weren't any from me.
I think you suggested the problem was the stud dog not any of us? But you are right in finding and funding more research for TVD. This wasn't intended to be a arguement, just wondering and yes, there will be a continueance in defending the stud dog, or if it had been the bitch I would have defended her. Your story lacks real proof as to who the carrier is of TVD. This is were many misconceptions come from and rumors arise about different dogs. So, yes stand in line to help with the funding and finding the genetic marker for TVD, I'll be right ahead of you!

If you look back at some old post on the subject you can find out more information. I found this which suggest that it not recessive, so it can get passed on by one parent and passed down several generation before showing its ugly head.

"The true mode of inheritance as established by Dr. Kathy Wright at the Cincinnati Children's Hospital, is a DOMINANT mode of inheritance with incomplete penetrance (an earlier misprint that was later retracted called it an autosomal recessive with reduced penetrance in dogs), which means that only one parent has to have the gene for TVD and that parent may or may have the disease expressed as TVD. The parent may test clear and pass the gene on to its offspring so some of those puppies may have the gene and either have it expressed as the disease or just carry the gene to pass onto the next generation."

If you read the posts this is what another study showed,so who is right?
That is why we need more studies on this.

Results—Heritability of TVD in this population of dogs was found to be 0.71, a value sufficiently large to suggest a segregating major locus. Subsequent complex segregation analysis did not provide sufficiently strong evidence to indicate influence of a major locus on the prevalence of TVD. However, complex segregation analysis for 2 categories of phenotype (eg, equivocal dogs were grouped with affected dogs) suggested that there was a single recessive allele with a substantial impact on the expression of TVD.

just gets more and more confusing to me - hence the reason we need to talk about this!
And to the poster who said they were unaware TVD was a big problem and that newborn pups can die from it...you need to go back to breeders school!
Gosh I wish there was actually a "breeders school"!!!
I have done the only thing I knew how to do, eliminated the pedigrees that produced it for me.

I'll bet with all your knowledge of everything that you are going to be the teacher right!
Just because you had a problem with TVD don't put the rest of us in your school!

I wasn't aware that a whole litter can die from TVD, how would you know if you didn't post the puppies?
As far as it being out there more then we think, I have heard of one or two cases in the last 2yrs. Have you heard allot of it, please share your experiences with us and how many are "more then we know"?
Not to get off the subject, I think there is more problems with seizuring then TVD. Just my opinion

Not according to the OFA Lab Survey:

http://www.offa.org/labradorsurvey.html

I've been in breeding and showing of my labradors for 40 years. In all that time I had just one case of TVD. My stud male had produced over 30 litters at that time. I couldn't think of no longer using him as he had produced 3 champions for me. I continued to use him for 14 more litters and never a problem. The bitch I used had already whelped 3 litters prior to the one which produced a TVD pup. She had 4 more litters prior to retirement. She never produced a champion for me but her pups were all excellent. She never had another pup with TVD. I also never put her with the same stud that had produced the TVD pup with her. So, is TVD hereditary? I can't believe so. If it is in the genes then I believe it had to be a bad combination.