False Pregnancy?

Question
Others have asked this - but this is a little different in that we were given a
Shetland pony mare last summer who had a filly at her side & a mini stud
running with her & other pony mares.  In the fall, we had the vet check her &
we were told that she was 60 - 90 days in foal.  We brought her home Aug. 4
so normally, she would foal around July 4th (that would go along with the
vet's estimate of 60 days).  We had the other vet from the same clinic come
out on July 10th to check our mini mare (who then foaled fine that evening) &
asked her to check my pony mare because she was not looking very pregnant
to us & she should have been due.  This vet did an internal exam & could feel
nothing.  She said there was no foal.  I was so very disappointed.  But now, 11
days after the mini mare foaled, my supposedly open pony mare has her bag
swelling!  Could she be having a sudden false pregnancy?  We just started
feeding a new crop of hay - lots of alfalfa in it & still a bit green - could that
make hormone changes in her so that she could make a bag?  Could the
other foal be making her hormones rage so that she thinks it's HER foal?  I'm
just wondering if a vet could possibly miss a foal when the mare was at her
due time?  

Thank you for any help/answers you can give me.

Penny

Answer
Hi Penny,
          The vet may have missed the foal due to the fact that it was far down the uterus. This is common if the Vet is not a reproductive expert.  The hay should not have caused a hormone change. False pregnancies are possible but rare in mares. Usually in a false pregnancy the mare shows the signs from start to finish. They will look pregnant and show all of the signs including but not limited to changes in body shape, color of the vulva, no signs of heat, ETC. I would get your mare ultra sounded this way you can see if she has a follicle or not. That will be the only way you will know for sure.

Lisa