More on Dwarfism and Research

[woodnldy]

Thank You Both John and Robin for all your information and hard work. Please keep us updated and let us know what we can do to help in any way, large or small. Is there anywhere a listing of blood lines that have seemed to through the dwarf characteristics more often?? I have one mare that has the Komoko's 2 generations back so i would realy like to know what to watch for in her foals. Does anyone else on the forum have a list of blood lines that have had problems?? you can PM or e-mail me if you don't want to put them in here. Thank You again for all the information.

 

[wcr]

John and Robin, thanks for the info.

John, you mentioned different types of dwarves and it would be interesting to see some pictures and what the different types you have identified.

 

[Arion Mgmt]

Stacey,

Blood from full sibs to a dwarf is not helpful right now, it would after the gene(s) are found and a test is made. Even parents blood of a dwarf without the dwarf sample is not any more help than the sibs. It is key to understand the reasons the actual dwarf sample is needed, it is because it is exihibiting the disease in homozygous form. The parents and full sibs if normal are not, but with the parents DNA using lab techniques I cannot explain here due to complexities and length, we can use comparisons to help us find the gene(s) faster than with only the dwarf, or only parents that have produced a dwarf. Key in genetic research is the collection of afflicted individuals and parents, without that you have just a "jumble of info" that would not really be useful in research of an affliction that none of the samples exihibit but possibly some carry. As it is now, with dwarf DNA and parent DNA it is still trying to find a needle in a hay stack, but we are looking in one hay stack of genes, not all of the hay stacks of genes in the field of unafflicated horses maybe with one copy of the gene. Poor analogy but I think you can picture it.

Also those of you that have dwarfs, pics and blood would be great, pedigrees with them even better and if parents blood available it is IDEAL. BUT I MUST have dwarf blood if alive, and pics. If any of you have dwarfs and put them down at birth I can use those as well. For those of you that have ones alive I would greatly appreciate blood and pics at birth, with parents blood and pics.

If anyone has a full term or earlier dwarf born this year and it is dead, I really need them for a bone size and density study comparing to normal newborn foals, UK and I will make the arrangements to have them shipped, whole body, this is because the whole body is to be digitally xrayed. I am doing this study with Dr. Swrezcek the equine pathologist at UK. This is to give HOPEFULLY a protocol to identify dwarfs early after they are born until a test is developed, if at all. This will hopefully make it scientific in our identifying and or denying registration questions on foals that are or might be a dwarf.

John

 

[Dandy]

Yes, like "Woodnldy" when I started the other thread it was to try to find out bloodlines that produced dwarves. It appears though that that would be most at some time or another. I still would be interested in knowing about stallions that were used that were dwarfs. Of course I know that could possibly be just someone's opinion about that horse. The only ones I have seen pictures of so far that I could say were dwarves (in my opinion) were the two posted on this site (Lord of Isles and Bond Tiny Tim). As I said before Lord of the Isles shows up in one of my pedigrees several generations back and I do have some Komokos bloodlines.

 

[AJ]

John and Robin - with all the research you have done, I am wondering where the following may enter the scene.. During course of researching/reading about dwarfism, I have run across this info : Hypothyroid Congenital Foal Syndrome which includes disorders of the Musculoskeletal System, deficiency growth hormones, abnormal thyroid hormone levels and nitrate nitrate toxicity theory. The foals described resulting from this are exactly like the foals described as dwarfs in the mini industry. Ongoing research continues in this area.

 

[Arion Mgmt]

AJ,

I looked up your case study that you sighted, it was done at the Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon. The link of the article from NCBI is here

http://www.ncbi.nlm.nih.gov/entrez/query.f...4&dopt=Abstract

The disease you are referring to is suggested to be caused by diets with nitrates or low in iodine given to mares during gestation. This is what is known as environmental influence of gene expression. But the genes are not altered in the horses, they are in environments that do not let the proper expression and utilization of you genes for your body to grow, the gene expression is in a way altered or sort of inhibited so to speak, but not mutated. Like with scurvy caused by lack of Vitamin C, or Rickets caused by the lack of Vit D which in turn causes lack of calcium absorption, both in humans.

I would not be suprised if this has happened somewhere in a mini mare, but the number of dwarfs and multiple types and being that they are in all parts of the country, even globe and that these dwarfs reproduce their characteristics, means there is a genetic cause not environmental. Also the paper mentions nothing of these foals being able to mature or even reproduce, our dwarfs do mature and can reproduce. Congenital means that it exists at birth, it does not mean that it is caused genetically.

John

John and Robin - with all the research you have done, I am wondering where the following may enter the scene.. During course of researching/reading about dwarfism, I have run across this info : Hypothyroid Congenital Foal Syndrome which includes disorders of the Musculoskeletal System, deficiency growth hormones, abnormal thyroid hormone levels and nitrate nitrate toxicity theory. The foals described resulting from this are exactly like the foals described as dwarfs in the mini industry. Ongoing research continues in this area.

 

[Minimor]

Thank you for your posting on that John.

As I posted on another thread several days ago, I had experience with congenital hypothyroidism in a Morgan filly in 1991. I talked with Dr. Andy Allen of WCVM Saskatoon at that time. I talked with him again last year after losing half our '04 foal crop to this same condition. Some time ago people on this board had referred to the deformities caused by nitrate poisoning, and when I spoke with Dr. Allen the last time, I specifically asked him about these leg deformities. He was a bit puzzled by the question, because actual leg deformities are not part of congenital hypothyroidism. He suggested that some people may speak of deformities but are actually referring to the leg weaknesses that are typical of the condition--weak extensor tendons which prevent the foal from bringing it's leg forward & placing it's hoof flat on the ground, swollen knees and immature bones in the knee &/or hock joints. Granted, the majority of his research has been on full size horses, which do not carry dwarf genes. These foals do often have an underbite, but they do not get the disproportionately large heads/domed foreheads that is associated with dwarfism. They do not have any tendency toward having the short, twisted legs of a severe dwarf. So, Mini foals that appear to be severely affected dwarves are not at all "typical" of horses with congenital hypothyroidism caused by nitrates/mineral deficiency.

After my last conversation with Dr. Allen I got thinking about it & talked about it with some horse people, and our theory is that in Minis that appear to be affected by something such as nitrate poisoning actually have something more going on. Is it possible that in horses that already have dwarf genes present, nitrate poisoning would cause these genes to be more strongly expressed? I have not yet made the effort to speak with Dr. Allen again & ask him his thoughts on this, & find out if recently he has had opportunity to see more Minis with the condition.

 

[MiLo Minis]

I just wanted to comment and say that I am glad that this research is being done and that the whole idea of euthanizing any dwarf gene carriers is not going to happen. I think that because dwarves are so abhorrent to look at we instinctively overreact. It has never been suggested that LWO carriers be euthanized but then, they are not abhorrent to look at and don't live long enough to make us realize how tragic they are - but they do suffer just as dwarves do. Research was done to isolate the gene and to be able to recognize it and therefore govern our breeding which is exactly what needs to be done here. Anytime an aberration (which our minis are) in breeding of an animal takes place you have to start somewhere. In the case of miniatures it was started with unusually small animals which of course means that a certain large percentage of them would have been dwarf in size. Good breeding has taken these animals and improved them to the point where they are not recognizable as having come from where they did - that is what good, responsible breeding does. A big round of applause for the ones responsible for this research and I can only hope that you will be successful in your endeavors.

 

[Teresa]

All I can say is God bless you for all the work that you have put in to your research. I want to print out all that you have said so that I can study what you have written.

Did I understand that you might get funding from AMHA? If not I think as concerned miniature horse owners, we did to contribute financially to your research that will benefit us all in your research.