Dwarfism and testing, Thoughts for the future

[stormy]

The recent post about dwarfism and hard decisions breeders must make got me thinking. Johns research is showing that their are at least 5 types of dwarfism, all recessive which means you only get a dwarf when the one of five the mare carrys matches the one in five the stallion carries, makes it much more possible to believe all or a large percentage of minis may carry one of the five as matching that one in five at mating because much less liely then if their was just one dwarf gene.

So the question is when the test is available how should breeders/the registry respond?? If a mare is found to carry the gene for one of these five possible varients of dwarfism should she be removed from the breeding herd if it can be verified the stallion does not carry the same varient??

Many breed FOR LWO, a lethal in its homozygous form and many have experianced the pain of losing a lethal white foal because LWO can hide itself pretty well...should testing be mandated for dwarfism (and LWO for that matter)??

With some thought as to how this test could impact the breed, could impact breeders who have spent many years investing in the best they can afford, could impact the registry as a whole.....what do you think the outcome of testing should/will be???

 

[ohmt]

Not quite how it works-there are 3 types I believe that can mix and match. Going to go try and find which ones those are as i know they were mentioned in John's notes somewhere on the dwarf forum.

 

[circlesinthesand]

hmmm, I dunno, I'm still so new to mini's that this is just something I'm constantly learning more about. But for an outside perspective maybe my thoughts will help.

If a test was available, I think there is a way to remove it...it WILL not happen over night. It will not happen in a decade, and it may not happen in the rest of my lifetime. But it CAN happen. SLOWLY!!!

I wish I could remember all the details of how the AQHA proposed to slowly removed HYPP from the gene pool. It was a gradual process of eliminating a positive homozygous horse H/H and I believe they're still working to remove the N/H horses. It has been slow but it kept the breeders from being put out of business and has worked toward removing the issue. If tests were available, the registry could require the breeding horses to be tested in their original paperwork. I remember that some horses were grandfathered in, where they could still breed and not be tested themselves but had to provide proof of the result on the foal in order to be registered, I think. The rules were changing every year and I've never bred Impressive horses, though I have trained a few HYPP horses and it's a horrible thing, that put me off of the breeding completely.

Here's a link to some of the history http://www.aqha.com/About/Content-Pages/About-the-Association/Services/~/link.aspx?_id=222E6490C1B04EDB9618B2CFAB7063E4&_z=z and how they went about removing it from the gene pool. The rules literally changed yearly for awhile there. I think they're still evolving too.

Again, I cannot emphasize this enough, it needs to be done SLOWLY. Breeders need to be encourage to think to the future but at the same time not have their lively hood threatened. The goals need to be to the common good with small but specific steps to bring the change about in a manner that everyone can tolerate. None of this can happen without available tests and concrete specifics that people can understand. With so many 'types' and some able to be compatible, THAT needs to be clearly defined and discovered before it can truly work.

 

[Mona]

What Susan wrote

Not quite how it works-there are 3 types I believe that can mix and match. Going to go try and find which ones those are as i know they were mentioned in John's notes somewhere on the dwarf forum.

What Susan wrote here, http://www.miniaturehorsetalk.com/index.php?showtopic=129098&st=80&do=findComment&comment=1475681 explains things a little better.

 

[Wings]

I imagine that when a test is available we'll first see the matings of carriers to non carriers and a system where the foals of carriers must be tested in order to find out if they to are carriers of dwarfism. Some registries might even call for mandatory testing of stock, maybe stallions to start with.

I personally think it will take a long time to breed it out just by looking at how things have gone for other breeds and thier genetic issues. But as long as we know the status of a horse and are not producing a dwarf I think we'll have come along way in that step alone.

 

[TPs flat rock acres]

if there was an excellent mare or stallion and there was a test to test them to see if they are a carrier why eliminate them? just try to breed away from it