Help me to understand

[Mona]

Also, breeding carriers to non-carriers will NEVER produce a dwarf. The non-carrier only give normal genes, and the carrier will only give a dwarf gene 50% of the time; so 50% of the resulting foals will be 100% normal and NEVER produce a dwarf, and the other 50% of the foals will only be carriers.

The above is a quote made by you in another thread. My question is, does this mean that ANY horse that produces a dwarf IS automatically at least one type of dwarf?

Also, I have a question in regards to the hypothyroidism/dwarf connection question you answered. I have read and re-read it, but I am not sure if you are answering to that specific case mentioned by the original poster, or if you are answering it in regards to all? You said:

I really believe it is suspect that hypothyroidism is causing all the dwarfisms, especially multiple types.

Does this mean you feel there IS DEFINITELY a connection link from ALL cases of hypothyroidism, or that you doubt it to be so?

Thank you for your time in answering these questions by all of us. This dwarf topic has been brought up many times, and we can only give educated/non-educated guesses, so it is nice to have you here to answer questions with your vast expertise!

 

[Arion Mgmt]

Mona,

Please reread out loud what you quoted me saying, I think you are confusing yourself.

QUOTE

Also, breeding carriers to non-carriers will NEVER produce a dwarf. The non-carrier only give normal genes, and the carrier will only give a dwarf gene 50% of the time; so 50% of the resulting foals will be 100% normal and NEVER produce a dwarf, and the other 50% of the foals will only be carriers.

If you have a stallion that is a homozygous normal, ie non-carrier for any dwarfism. This means he has NO dwarf genes, and he is bred to mares that are carriers of any of the dwarf genes, are you going to get a dwarf. Answer NO NEVER, The nomal genes are dominant, all of the foals will be normal, HOWEVER, 50% will be carrying a dwarf gene inherited from the mare.

A carrier is NOT a dwarf, it is a carrier of a recessive dwarf gene, it physically and conformationally is a normal horse, gneetically it is carrying an inferior gene not being expressed.

To speak more plainly with regards to the hypothyroidism and dwarfism, I do not at all believe the dwarfism in the Miniatures is caused by hypothyroidism

It would be very foolish to think that miniatures all over the world are that are having dwarfs are all hypothyroid, they would all have to be genetically and environmentally inthe same situation, meaning same environments, and same genetic suseptibility for having low thyroid hormaone prduction.

BTW reread what I wrote about my questions to her---

quote from the other thread I wrote--

"To try to critically examine your concern. Of those cases you have knowledge of about hypothyroid mares that have had dwarfs, have ALL the foals been dwarfs from ALL of those hypothyroid mares??

And your answer is -- "All of these mares had had previous normal foals prior to the thyroid going out of balance."

How do you know if the mares were hypothyroid before with the normal foals?? Were the mares tested for hypothyroidism during the gestation of the normal foals?? Were they tested for hypothyroidism during the gestation of the dwarf foals?? That would be the ONLY way to correlate the dwarfism is caused by the hypothyroidism in the mares. AND hypothyroidism would have to occur every time in the mares to produce a dwarf everytime, and on top of that the dwarfs would need to have very similar characteristics.

How old are these mares now that they are hypothyroid?? Hypothyroidism can be late onset due to age, known to occur in older and geriatric horses. "

It would be very SUSPECT for someone to believe that is the cause of the dwarfism, without acknowleding any of the known genetic problems we have and our history in breeding dwarfs.

I hope this cleared it up.

John