Thank you for posting.But she may also foal much earlier - I would not rely on a "due date" based on 349 days.
We start watching the mares closely for any changes at 300 days... and have had healthy full term foals arrive even at 296 days.
My mare has been bred during the same week in May, and has routinely foaled the last week of April. And, I took the 349 from her last foal. I wouldn't doubt if she did foal earlier, but I will be having a VERY close eye on her once March/April hits!
