Hello Dr. Valentine. I know this is a bit out of your area of expertise, but, have you ever heard of a connection between thyroid and a mare coming in for long cycles (and being very horsey ... i.e. my daughter's 22 YO mare is horrible).

Her throid came back at (ah, I think he said 10 and he prefers them to be at 20 - whatever that means I have no idea and will need to ask him).

Thyroid testing is very difficult in horses, as they can often have very low levels in blood even though nothing is wrong with the thyroid. At this age, though, you could have a more generalized endocrine condition due to pituitary dysfunction (Cushings), which can cause low thyroid test levels. I suspect that this is not a primary thyroid issue but re-testing and ruling out Cushings could be important. I'm sure your veterinarian has also palpated her ovaries to make sure there is not a tumor or cyst there. It could easily be 2 unrelated problems and it may be difficult to sort them out. I hope this helps to shed some light on a complicated subject, but that's the way the endocrine glands (and some mares) are :)

Yes, he palpated her and found nothing. Interestingly, her personality doesn't change at all she just is staying in season. I will speak with him about Cushings - I'm surprised he didn't suggest it to start with.