I suppose it depends on the age of the mare. If she’s had foals, especially in the current year, then no, because obviously she’s got all the right piece-parts, and it’s not likely a biopsy score would be that poor. COULD it be? I’m sure it could. Then it might come down to the cost of the mare and whether she could be a riding horse instead.
That would be a BSE before purchase. I may very well do one after purchase, depending on the time of year. If it was January and I was thinking of breeding in April, for example, I’d probably wait a month to have her as recently clean as possible before breeding
If there was something minor, and 6+ months before breeding, I would clear it up now, then check again in the Spring.
But I did buy my mare without a BSE - but she was a 3yo coming off the track with a Caslick. However, she was first a companion horse, 2nd a potential riding horse, and a close 3rd a potential broodmare (and she is pregnant now, everything was perfectly clean when checked in the Spring).
So it all does come down to what the options are and how much the mare is- for me 