# Is Congenital MegaE genetic?



## ldpeterson (Feb 13, 2005)

No, I'm not planning on breeding Maiya but am more curious than anything as there is no clear cut answer it seems. Of course there is no clear cut answer on anything related to MegaE. *sigh*

Obviously if you had a MegaE dog you wouldn't want to breed it anyways, but does there seem to be a genetic pattern or is it just a fluke thing that pops up once in a great while? Is the whole litter usually affected or just one puppy? 

Just some curious "dog breeding newbie questions" what do you think?


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## JeanKBBMMMAAN (May 11, 2005)

Here's a start: http://www.upei.ca/cidd/Diseases/GI%20disorders/megaesophagus.htm


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## ldpeterson (Feb 13, 2005)

> Originally Posted By: JeanKBBMMMAANHere's a start: http://www.upei.ca/cidd/Diseases/GI%20disorders/megaesophagus.htm


You are the link queen!


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## JeanKBBMMMAAN (May 11, 2005)

I want a crown! 

I love that site-it has so much good (scary) information.


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## ldpeterson (Feb 13, 2005)

> Originally Posted By: JeanKBBMMMAAN I want a crown!
> 
> I love that site-it has so much good (scary) information.


LOL! 

Yes, I actually have that site bookmarked lol and didn't even know it. I guess I didn't read about the breeding part. Obviously it's genetic in a few breeds (from what it says), but still unknown in others. It has a lot of good/scary information and it's even scarier when you live it everyday! 

I was thinking of all Maiya's siblings and wondering if they were affected too.


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## JeanKBBMMMAAN (May 11, 2005)

And I wonder if the reason it may be "unknown" in other breeds is that research hasn't been done. 

I will participate in any trial, any time I can with Bella and Nina to help the breed out. They did the IgA deficiency one-and that information ended up helping Nina. I wish there was a clearinghouse of information for studies that would send out notices when your breed or disorder is being studied. 

It has to be scary to live with. 

Hopefully other people will have more info. on known practices.


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## ldpeterson (Feb 13, 2005)

I doubt it's been studied very much. It should be though as it's a CRAPPY disease that so many dogs get euthanized for because vets are so uninformed on how to manage it. 

Obviously many people wouldn't want to go as far as we have for Maiya, but we are weirdos anyways.







However, if it got studied more perhaps they could find better ways (easier ways) of treating it. I don't know why this one seems to be put on the backburner. 

I would love to participate in a study on this. As much as I love Maiya I even thought of donating her body (when she's gone and hopefully that will be forever from now) to A&M for studies. I don't know if you can do that though, but would consider it to help others.

I hate to see anyone else go through this and the info on it is sooooooo limited you can only go through others experiences if you want anything other than the basic information.


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## EastGSD (Jul 8, 2001)

With puppies born with Mega you have to investigate and find out if it is a result of a persistant right aortic arch....then yes, it is inherited for the most part.


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## Chris Wild (Dec 14, 2001)

PRAA and MegaE are not the same thing. 

PRAA is caused by the arterial shunt that allows bloodflow around the lungs in utero to fail to atrophy and disappear after birth like it's supposed to. This arterial shunt remaining intact causes constriction of the esophagus near the heart, which in turn can lead to pouching of the esophagus before the constriction, as food backs up due to the bottleneck. 

This is very different from an enlarged esophagus caused by MegaE. The esophagus of a PRAA dog is normal sized and functions normally, before and after the constriction. The difference between true MegaE (enlarged esophagus) and PRAA (bottleneck causing a back up) is very obvious on barium x-rays.

MegaE is genetic. PRAA is congenital, but is not considered to be genetic. It is something that happens in all mammals, including humans, though it is more prevalent in some breeds of dogs more than others.

Good news with PRAA is that if it does cause a problem, it can be fixed with surgery. For MegaE there is no fix, only management of the symptoms.


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## ldpeterson (Feb 13, 2005)

How common is congenital MegaE? The articles I read make it seem like a rare find, but the vet doesn't seem to think it's all that rare. 

I know there are a lot of breeders on this board and am wondering if you've seen a lot of this disease or even encountered it suprisingly in your own litters. 

Sorry for stupid questions but I'm just interested in the prevelance, and genetics of this illness, especially in the GSD.


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## EastGSD (Jul 8, 2001)

> Originally Posted By: Chris WildPRAA and MegaE are not the same thing.


I did not say they were the same thing, I said to be sure that a PRAA is not causing the Mega. PRAA can cause mega by interferring with the function of the esoph. due to it's presence.

Cherri


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## Chris Wild (Dec 14, 2001)

Absolutely if a dog is suspected of MegaE, it is very important to determine if it is true MegaE, or PRAA.

But PRAA can't cause MegaE. PRAA can cause a condition *similar to* MegaE, where portions of the esophagus are enlarged, and symptoms are quite similar. But it cannot cause the genetic disorder dubbed by the veterinary community as Megaesophagus.

Semantics, I know. I'm sure you know the difference, but others may easily misinterpret your statement to infer causation of MegaE. Therefore, I think it important to point out that PRAA and MegaE are not the same disorder, and one cannot *cause* the other. Especially in a thread discussing the genetics of MegaE. They are two different disorders with different physiology, causes, inheritance, and treatment options.


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## MaggieRoseLee (Aug 17, 2001)

My ElsaRose has megaesophagus and it's absolutely genetic. Problem is so many breeders either don't know about it, or ignore the situation so pass it on (specially all the back yard breeders). To complicate the situation it can show itself very differently in our dogs. From killing some puppies soon after birth because they can't get food properly, to some pups only showing the condition when they go to solid foods, to other puppies barely showing any problems and even growing out of it by adulthood!

More resources are:

http://www.marvistavet.com/html/megaesophagus.html

http://www.vin.com/VINDBPub/SearchPB/Proceedings/PR05000/PR00133.htm

http://www.videxgsd.co.uk/gastrointestinal.htm

http://www.thepetcenter.com/xra/xraycases.htm#Hip%20Dysplasia

http://pets.groups.yahoo.com/group/megaesophagus/


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## gagsd (Apr 24, 2003)

Is there any data on lines that may produce MegaE in GSDs?
Mary


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## Chris Wild (Dec 14, 2001)

> Originally Posted By: mamagooseHow common is congenital MegaE? The articles I read make it seem like a rare find, but the vet doesn't seem to think it's all that rare.
> 
> I know there are a lot of breeders on this board and am wondering if you've seen a lot of this disease or even encountered it suprisingly in your own litters.


We've had 1 pup with PRAA. Never had a pup with MegaE. The only dog I've ever personally known or seen in person with MegaE is MRL's Elsa Rose. Our vet sees a lot of large breeds, and a lot of GSDs including a couple good, and several not-so-good GSD breeders in the area, and he said he encounters a couple cases a year, but nothing to indicate it's pandemic.

That however is something that I suspect would vary from region to region. Being genetic, it's going to run in some families and not in others. So a geographic area that has a larger number of dogs from any aflicted bloodline is going to see more of it.




> Originally Posted By: gagsd_pup1Is there any data on lines that may produce MegaE in GSDs?


There isn't any database or such, no. Like most genetic health issues, the only way to find out is to ask around and gather info by word of mouth... and of course be able to ferret out truth from rumor.


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## EastGSD (Jul 8, 2001)

> Originally Posted By: Chris WildAbsolutely if a dog is suspected of MegaE, it is very important to determine if it is true MegaE, or PRAA.
> 
> But PRAA can't cause MegaE. PRAA can cause a condition *similar to* MegaE, where portions of the esophagus are enlarged, and symptoms are quite similar. But it cannot cause the genetic disorder dubbed by the veterinary community as Megaesophagus.
> 
> Semantics, I know. I'm sure you know the difference, but others may easily misinterpret your statement to infer causation of MegaE. Therefore, I think it important to point out that PRAA and MegaE are not the same disorder, and one cannot *cause* the other. Especially in a thread discussing the genetics of MegaE. They are two different disorders with different physiology, causes, inheritance, and treatment options.


Chris there are multiple causes of mega like symptoms. Yes PRAA can cause these symptoms as can a host of other disorders.

My point was for the poster to craefully evaluate and look for what is causing the mega (which is an overstretched esophagus.) The point is the dilation....not just calling it "mega." It is like saying a puppy has a "heart murmur" disease....the murmur is but a symptom of an underlying disorder not a disease in itself....and it is important to find out what is causing it. Mega can come out of no where for no reason but more often than not a source can be identified.

Cherri


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## MaggieRoseLee (Aug 17, 2001)

> Quote:Mega can come out of no where for no reason but more often than not a source can be identified.


I'm not quite sure what's meant about that statement.

But what I do know is there do seem to be 2 types of mega. One is the genetic form puppies are born with, and this is the one I have quite a bit of personal knowledge about. The one I do NOT know as much about is one that occurs suddenly to older dogs with no warning or seeming cause. (this maybe the one EastGSD is thinking about?)


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## middleofnowhere (Dec 20, 2000)

I thought congenital meant linked by genes, meant able to be inherited.


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## EastGSD (Jul 8, 2001)

Couple of things that may help.....as I said there are a number of disorders that can cause the symptoms of mega and it can be either developmental/congenetal or aquired....what is mega? Megaesophagus is basically an overstretched esophagus that is not functioning as it should with the normal muscle movements that propel food toward the stomach. Strictures, PRAA, abnormal development, thyroid issues and other things can cause issues with this. Congenital means present from birth....not all congenital things are inherited, just there from birth. Genetic means it was and is controlled by genes and inheritance. Mega, the inherited version, can be autosomal dominant (meaning only one gene need be inherited from one parent with various levels of effected state) or may be autosomal recessive in which each parent contributes one gene. The GSD is increasingly affected by this disorder and it is felt that there are many carriers that are not identified. Due to this it can be difficult to map....we need a genetic test for it. No affected dogs should be bred at all as it only contributes to the carrier state within the breed.

Here is a good article
http://www.videxgsd.com/gastrointestinal.htm


Cherri


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## Chris Wild (Dec 14, 2001)

> Originally Posted By: middleofnowhereI thought congenital meant linked by genes, meant able to be inherited.


Nope. Congenital just means present from birth. Genetic means inherited. Some congenital issues are genetic, some are not.


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## ldpeterson (Feb 13, 2005)

> Originally Posted By: MaggieRoseLee
> 
> 
> > Quote:Mega can come out of no where for no reason but more often than not a source can be identified.
> ...


3 types. Congenital (dog was born with it), secondary (dog has acquired it due to other illness), and idiopathic (dog has acquired it in later years for unknown reasons). 

From the many articles I have read on MegaE it seems as if an identifiable cause is only found in only small percentage of cases. Usually it's Myasthenia Gravis or thyroid disease. 

If the esophagus has been stretched out large enough for long enough despite the treatment of the underlying disease or anomoly causing it, it may never return to complete function.


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## ldpeterson (Feb 13, 2005)

> Originally Posted By: EastGSD
> 
> My point was for the poster to craefully evaluate and look for what is causing the mega (which is an overstretched esophagus.) The point is the dilation....not just calling it "mega."


Maiya has been tested for every disease that comes to mind when we found out she had Mega. Her esophagus is stretched beyond what even a typical Mega dogs looks like. Given that she was a rescue we have no idea what her puppyhood was like, but the vets and the specialist all say they are almost positive she was born like this as they can find no identifiable cause. They say that the idiopathic "version" of it does not pop up until the "later" years. Certainly not at 2 years old. 

What they say pretty much verifies everything I've read and vice versa. It seems that much is agreed upon.

Maiya can't be helped beyond managing her condition which is what we are doing. I've come to learn first hand how devastating this disease is (more devastating is the aspiration pneumonia that often accompanies it), and started thinking about the genetics of it. 

Just grappling for any info I can get for educational purposes. Not even sure what I'm looking for. I read a lot of MegaE from the doctor's prespective, I guess I'm now looking for the breeder's prespective.


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