What's bolded second sounds legit to me. Sounds like she's a mild roarer and needs that surgery. I've never heard of it being the result of a throat infection before, but I guess it's possible.
The first part? I dunno. And why you'd put that in the ad, I dunno either.
Finally, what breed of horse is this? A 10,000 dollar weanling? What's the price on her now?