"Below is a link to an article written that gives a slightly different description of the affected foals with congenital hypothyroidism due to Nitrates. This article describes them with an underbite..and also notes references. Does this sound disproportionate? Thank you for taking your valuable time to help us all learn more about dwarfism.
Congenital Hypothyroidism in Foals"
I think you need to refer to my last thread about nitrates and review the websites I refer to for explainations on disproportionate dwarfism.
Ok so now someone says it causes unnderbites as well, that is not suprising, since the toxin is affecting the abnormal growth and development of the mandible. The foals still do not have a severe domed head, shortened and malformed long bones of the legs. All of those photos are of big horse foals with normal length to their leg bones, the only mini is the little black Miniature foal. It looks normal and it is saying it is immature?????? Immature to what?, a large horse foal?? They show no comparison of another Miniature foal that is "mature". I will say his ears sure are not "floppy", they came up for the photo. I have yet to see a Miniature dwarf of the types I study to show any of these symptoms only and nothing else. All of mine show very abnormal leg bone growth as well as hip, spine, jaw, and head malformations, etc.
Unless I am blind I do not read anything that states that this is causing disproportionate dwarfism to the long bones of the foal's body or that it even causes any malformations of the head other than to the mandible causing an underbite.
Underbite is a known inheritable genetic defect as well, totally on it own with no other malformations to the foal. If you look in any equine conformation handbook or breeding reference manual they clearly state that underbite or"monkeymouth" is an inheritable genetic trait that is undesired irregardless of anything in the environment or other genetic or congenital defect that could cause it as well.
What if the underbite wasnt due to the toxicity but was a genetic defect the foal inherited, are they sure it is only due to nitrates. All of the other nitrate toxicity documents I have read all refer to parrot mouth as one of the signature characteristics
If you go to the bottom of the pdf. You will see this hyperlink below to the thesis paper of the reference Dr. Andy Allen. In this paper it very clearly states the region of the country Western Canada, Western Ontario, and Northwestern US, that are shown to be affected. They do not state this is occuring all over the world in mass.
http://library2.usask.ca/theses/available/...0212004-000356/
He clearly states the variables involved and that this was a case controlled study, ie, these mares and foals were Guinea pigs for this experiment, and were fed a very high level of nitrates. I can make just about anything I want to happen congenitally with any given experiment of a specific toxin. This was an experiment, this was not an out in the field study of what is really going on. They clearly state that certain examples were seen in that region of the countries and they suspected nitrates as the cause of certain congenital deformities, so they did an experimant to show what nitrates can do.
It is starting to sound as if some of you are taking a known toxin and its effects on fetal growth and blanket applying it to any abnormality you see in the Miniatures, genetic or not. I dont get it. I am not saying there are no cases of hypothyroidism in the minis, on the contrary I know it exists, as it does in other horse breeds. And I am not saying that there arent any cases of Nitrate toxicity in Miniatures, on the contrary I am sure it has and will happen, but to blame everything wrong conformationally, congenitally or genetically in the minis on Nitrates is really not thinking things with a rational, critical mind. Are we going to blame all of the dystocias and foaling problems in the Miniatures all over the world on Nitrates too, and ignore their size as probably THE major factor??
I know of other toxins, drugs, etc., that can cause similar physical characteristics that are shown on that pdf. I just dont see how you CANNOT distinguish between characteristics of different diseases whether genetic, congenital or environmetally induced. There are differences in their etiology I will not go into here about all three. I would be literally writing a book.
I am not belittling this toxin, I just do not see a single glaring similarity other than a slight under bite in one photo,the head is even normal in shape, and it is a large horse foal, not a mini. Dwarfs have numerous other characteristics that do not coincide with nitrate toxicity.
John
