Just curious though, do those of you that have and breed mares with known thryoid problems disclose this to potential buyers? Including foals from these mares?
That's a good point/question Michelle. As for this mare I just had tested, I have her only live foal(before this year) here. She is 4 years old now, and just foaled her first this year. So there were no others to inform anyone about. This daughter I have though, settled easily, on her first cycle bred, and carried to term, with no problems. She is not overweight like her mother, so at this point anyway, shows no sign.
My other Hypothyroid mare, I told the people when I donated her to their program that she had a low thyroid and that she would have to be on Thyro-L and sent a supply with her to keep them going for some time. However, I know for sure that she had 2 colts and a filly before I bought her. Then when I owned her, she had given me 3 fillies, but it wasn't until her being heavy in foal with the 3rd one, that she foundered(maybe laminitis? I never knew there was a difference until a previous thread about low thyroid). There was no reason that I could think of to cause that, so Miniv here on the forum suggested I test for thyroid, and sure enough, she was right! I did sell that filly, but I don't recall if I told her buyer about her dam being low. If I did, it would have been just in general conversation, and not as an alert, as I never would have thought of it actually.
I know that 2 of her 3 fillies that I sold from this mare, have had multiple foals, and as far as I know, have not shown signs of hypothyroidism. I know the owners though, so I sure can tell them about it. Maybe a bit late now that they bought them, but as I say, it's not something I would even think to mention, as I never thought about it being hereditary??
All this said now, I would DEFINATELY disclose the fact to the new owners(if I ever decided to sell) that the mare herself is low thyroid, because she needs to be on meds to maintain proper levels.