how common is a false pregnancy in a mare?

Question
  My 23 year old mare----whom I did not breed---Has a large belly-edema-
and swelling in her legs--and has white milk coming off her teat.
   She had been bred and sucessfully carried and delivered two foals 2006 and
2007.   I'm  very confused.   Please respond!  Joy

Answer
Hi Joy- It very well could be a false pregnancy- We had this happen in an older mare also.She looked bred the whole time and bagged up- then one day she looked normal again. Is there any way possible she has been around a stallion? If not- I would call the vet for a check-up- I wouldn't worry too much unless she starts acting different. i wish you the best of luck with her!!