# Clarifying the MHC Mumbojumbo....



## fjm (Jun 4, 2010)

Thanks - very useful summary and links. It will be interesting to see the effect this new research has on breeding practices.


----------



## whitepoodles (Jul 5, 2010)

An EXCELLENT post, thank you


----------



## Yaddaluvpoodles (Mar 20, 2010)

Thanks.
This is really significant and the results of MHC testing may have a tremendous impact on our poodles.

Re: standard poodles... there are not a lot of MHC haplotypes in the poodles have been tested so far. I have heard that there have been either 4 or 6 haplotypes identified so far, depending on who I hear from. That's critical. That's not enough for long term survival of a species. Hopefully more people will have their poodles tested... and some more types turn up.

Here is a link to an easy to read PDF with a bit more information about the MHC.


----------



## whitepoodles (Jul 5, 2010)

Hi:
There is no link attached.


----------



## Yaddaluvpoodles (Mar 20, 2010)

Thanks! Here it is: 

http://www.west-of-england-collie-society.co.uk/public_html/mhc halotypes.pdf

I'm sure there's something wrong with these computers....they are so consistant on not putting my links in.....:embarrassed: (said a tad bit sheepishly)


----------



## whitepoodles (Jul 5, 2010)

LOLOL dont worry, I have done worse.. :)

I am totally computer illiterate. I get excited if I am able to upload a photo


----------



## papoodles (Jun 27, 2011)

Thank you for this post- I learned so much about MCH Haplotypes, and even better I can follow you 
I have an 11 yr old S.A. afflicted Shangri-La poodle so this research is of particular interest to me. 
I hate that Missy has to suffer such a nasty ailment because of inbreeding-and it is just not fair to decimate the ranks of S.P. because of human interference.
Question, please?
I tried to pull up the You tube link- but insted of talking science, I get a hockey fight! 
Thanks so much!


----------



## Yaddaluvpoodles (Mar 20, 2010)

Just checked out the Youtube link.. guess I've become a hockey fan! Not sure how that happened. I'll post a couple of links here, they are on the video list for the hockey game, so if the link doesn't work, if you go through the video list for that person (there have 39 videos on their list), there are some videos which deal specifically with MHC.

YouTube - ‪leaffan27's Channel‬‏

YouTube - ‪leaffan27's Channel‬‏

If you just go to Youtube and do a search for MHC there are quite a few educational videos.. some good, some not so good.


----------



## papoodles (Jun 27, 2011)

Thank you, Darla! The hockey game was easier to understand! Had to watch the videos more than once to understand what they were talking about. I was fascinated by the intricacies that underlay the constrction of the MCH haplotypes. Nature really works miracles..


----------



## Yaddaluvpoodles (Mar 20, 2010)

The MHC stuff is really fascinating. In tests with humans, they found that women were attracted to T shirts that had previously been worn by men.. who had different MHC's then the women did.

There has been testing done in human couples, who have spontaneous abortions and homozygous MHC has been found to play a significant role in many of those cases (back to dogs here.. so how might that cross over to bitches who don't produce puppies when bred to certain studs...)

Even in closed populations of wild animals, animals were more attracted to mates who had different MHC's. This is done based on smell (think hormones/pheromones). In domesticated animals, where we humans choose the mates, the way our dogs smell is not usually taken into consideration when making breeding plans-LOL. 

But now MHC testing is available. Yup, it is a genetic test.


----------



## CharismaticMillie (Jun 16, 2010)

Interesting!

Yadda, what do you think of this MHC test? Does it have a place in breeding poodles?


----------



## Yaddaluvpoodles (Mar 20, 2010)

I believe that the MHC is going to become one of the most important health tests we have and I am guessing that within the next 5 years it will top the list of essential health tests. The biggest problem we have with it is that very few people are even aware that it exists, or knows where to find out about it or where to have it done at.

The next biggest problem is this: we are just starting to learn about the individual MHC's. There may be some that are less desirable then others.. and right now, we don't know whether or not that is the case.

This could start a whole debate.. and I envision me getting lynched at the end.. or in the middle.. or at least somewhere along the line but:

If you have to prioritize health tests based on importance to your breeding program (I know, I know.. all health tests are important) this is how I (emphasis on "I") would prioritize please keep in mind that I have standards, the list would be a bit different if I had smaller poodles:

MHC
vWD (Vet Gen only)
NEwS
DM

Blood panel with CBC and chemistry
thyroid (Dr Jean Dodds panel)
SA
CERF
hips (if I had unlimited funds, I would do both an OFA and PennHip simultaneously, if I have to choose which one I prefer out of the two.. it's gonna be PennHip and if I have to choose which one I can afford, more than likely it's gonna be OFA)
cardiac ultrasound
JRD

The above list is my ideal and no, that is not what is done on my poodles. Sigh. I wish I lived in an ideal world. Anyone who has issues with what I have or haven't tested for, I gladly accept paid testing! <VBG>

Ok, now here's why I posted my list the way I did:
MHC--based on what research we currently have on MHC, diversity at the MHC provides a significantly higher functioning immune/autoimmune system.

vWD, NEwS and DM--These tests are genetic tests with a super high level of accuracy.

Most other health tests only give an picture of the health of the parent dog that is good only for the instant it is done.. and then only if that picture is interepreted right by the person doing the interpretation. Frequently there are things which can influence the results.. that really don't have anything to do with inheritance or genetics. For that reason, I feel that genetic tests that give a "sure deal" on results are a priority over all other tests.

Blood panel and thyroid studies-- Give a bit of insight into the overall health of the dog. That being said.. I have had both a symptomatic Addisonian, as well as a poodle with a massive tumor have labwork that came back NORMAL. 

I do not do, nor would I consider doing an ACTH stimulation test on a healthy appearing, asymptomatic poodle. However, IF I had lines which had a strong family history of Addison's, close up, I may change my mind. The reason I wouldn't do it is this.. although Addison's is very insidious, there are usually SOME symptoms. In order for the ACTH stim to indicate Addisons, the adrenal glands have to be significantly destroyed. I would be expecting to see some symptoms.. something abnormal. If I'm not seeing anything even slightly abnormal, not going to go there at this time.



SA biopsies--We've covered this elsewhere on a different thread. In most cases, the life expectancy of an SA dog is less than 3 years from date of diagnosis. I'm eagerly awaiting the results of the study currently being done at UC Davis.. regarding correlation of SA expression and MHC....

CERF-- simply here cause I think that they are less important than bloodwork, but more accurate then hip xrays.

Hips--bottom of my list. Ok, here comes that noose! Hip xrays are one of the most subjective tests out there. The same xray can be read differently on different days.. by the same technician. There is a huge difference between PH and OFA--they look at two different things, so comparing the two is like comparing apples to oranges. I prefer the info that PH gives me. I've also seen PH xrays that were redone.. with an improvement of 30 percentile. I've seen OFA xrays which indicated a dog was dysplastic, which was nothing more than poor positioning. I've seen OFA excellent xrays where I would SWEAR I saw remodeling on the xray. Then you get into the whole "what caused it, how is it passed on" thing with bad hips. Guess what.. not only is it not all genetics, but there is a terrific amount of environmental factors, even diet that can contribute to HD. I do consider Xrays as a tool in breeding decision making, but a very inaccurate tool at best. There have been a lot of poodles as well as other dogs removed from breeding programs over the years as a result of flawed xrays/and or results.

JRD--okay, I know this is a genetic test.. but quite honestly, I lost confidence in it initially. I'd love to have it done on my poodles, it hasn't been, but RIGHT now, as of this moment I don't consider it critical to my poodles. If I have a produce a pup with kidney issues, or have an adult (JRD is NOT limited to pups) with kidney issues, I'm going to be crying the blues and eating my words. The simple reality of it is.. I don't have the financial means to be as idealistic as I wish I could. For me personally, it is a sore spot, a huge disappointment which leaves me less than fulfilled. But I can only do the best that I can. 

We are fortunate to have as many tests at hand as what we do. When I think back (ha! I'm not that old...) to before there was all this testing, and how breeder's made choices based on what they could see in front of them.. and gut instinct. And quite honestly.. they seemed to have done quite well, until our big genetic bottleneck, sans testing.

Back on my hat box.. I sincerely believe that the BIGGEST and most important thing every breeder and every pet owner out there can do is to register their health issues with PHR. We can do all of the health testing in the world, but if we have health issues in our lines that we aren't sharing, or we are covering up.. that testing doesn't really matter a whole lot over the long term. 

We've all seen thread after thread that advocates only purchasing pups from health tested lines.. and yup.. I'm gonna advise that too. But if I were to go puppy shopping.. would I consider a pup from lines that weren't health tested? The answer to that is.. a 100% definate yes. Why? Because I'm going to do a whole lot of pedigree research first, to see what I can find out about the health issues in the family lines. THAT is going to carry more weight with me, then any CERF, SA, Xray or any other non-genetic test out there. We get caught up in the propaganda of testing, the rights, the wrongs and we often fail to see the entire dog. Now if I were to go pup shopping and was looking at untested lines and had the option of doing ONE single test.. what would it be? I would choose to do an MHC without hesitation--hoping for an MHC that is heterozygous.

Long opinion, there it is, please remember.. it is.. what it is, a personal opinion.


----------



## CharismaticMillie (Jun 16, 2010)

Yaddaluvpoodles said:


> I believe that the MHC is going to become one of the most important health tests we have and I am guessing that within the next 5 years it will top the list of essential health tests. The biggest problem we have with it is that very few people are even aware that it exists, or knows where to find out about it or where to have it done at.
> 
> The next biggest problem is this: we are just starting to learn about the individual MHC's. There may be some that are less desirable then others.. and right now, we don't know whether or not that is the case.
> 
> ...


Thank you, for taking the time to write this out, Yadda. Even though it is your opinion, it is full of facts, and it is only through a combination of facts and others' opinions that we can begin to understand all of this.


----------



## papoodles (Jun 27, 2011)

*'Who Knew Cancer Could Be Catching'*

I just finished reading the week-end issue of the Wall Street journal, where there was an article on the MHC gene- in dogs. And I was esp. thrilled that I even knew what the MHC gene was, thanks to you, Yadda!
The article is titled: 'Who Knew Cancer Could Be Catching', authored by Matt Riley
Apparently there is a world wide genital cancer epidemic in dogs, which is transmitted during mating. What the cancer does is to set "up home in new victims before the old one dies", and the thought is that somehow, that the tumor has evolved in such a way that it suppresses the activity of the MHC gene.Fascinating read!
The other point made in regards the MHC gene was that "it may have evolved in the first place as a defense against invasion by contagious cancers".
Could it be that because of the inbreeding and the suppression of these MHC genes, so many of our modern day dogs succumb to cancer?


----------



## Yaddaluvpoodles (Mar 20, 2010)

I'm seem to be technically challenged this week. Did a brief reply and didn't ever manage to get it posted (while simultaneously losing replies to some PM's GRRRRRR!)

*Could it be that because of the inbreeding and the suppression of these MHC genes, so many of our modern day dogs succumb to cancer? *

I would have to say a huge YES, however, the particular type of contagious venereal cancer they were talking about in the article is unique in the manner that it is transmitted (most cancers are not contagious or transmitted). There are a number of causes for cancers and every critter/human has cancerous cells in their bodies all of the time, but the immune system usually does get rid of them before they can replicate enough to get out of control and become a problem. Some cancerous cells do produce "immuno-modulating" chemicals.. which means that the chemicals are capable of influencing the immune system.. and making the immune system not recognize them as "bad" or atypical. If a dog has a homozyogous MHC, the functional capabilities of that MHC are already limited and as the MHC regulates the immune system, well.. guess what. If a dog has a heterozygous MHC, the immune system is much more powerful and flexible, over all, healthier... and probably more resistant to cancer.

Cancerous conditions are very complex and specialized, what makes one dog "susceptable" and the next dog not? I believe that MHC diversity plays a significant role in that. But... there are so many things going on environmentally, ranging from water contaminants, to impure air, to food additives, to contaminants to the vaccines we give, or sometimes the vaccines themselves.. etc. 

So, my personal opinion is that.. yes, inbreeding.. which leads to MHC homozygosity is a signficant contributer to why so many of our dogs are succombing to cancer.

There is a fun, easy to understand, very dramatic You tube video that talks a bit more about immunity and MHC. If you watch it through almost to the end.. when the Supressor T cells come in.. it will give you a bit of an idea of what happens in autoimmune disorders.. those Supressor T Cells don't get triggered and as they say in the video "Killer T Cells are Blood Thirsty!".


----------



## papoodles (Jun 27, 2011)

I didn't like the ending at all 
Thank you soo much for providing such a clear, easily understood overview of the science behind what's keeping us alive.
How very complex and fascinating..and it is scary how much we don't know!
Thank you again for taking the time to post this.


----------

