How can I help prevent my horses from aborting their foals?

I have four pregnant mares this year but recently one just aborted at around 6-7 months. I have never had this happen before and was wondering what I could do to prevent the others from potentially doing this. I would really rather not use regumate since it is something I would have to give them everyday. They get their yearly spring shots, good alfalfa hay, free choice of mineral and salt, and a highly concentrated pellet so I can't see the issue being the nutrition. I have a foal due at the end of this month, late April, and May.

Where do you live? If you are in an area where there are raccoons and possums they do carry the virus that is like when cattle get Brucolotis or Bangs. Which can cause abortion in horses. The only time we had a mare abort a foal was when we had a pet racoon who stayed in the hay barn.

Lilian was close...it is called Brucellosis. What shots do your mares get in the spring? The American Association of Equine Practitioners recommends mares be vaccinated against Equine Herpes Virus...Type 1, known as EHV-1 causing abortions in mares. Below are the guidelines:http://www.aaep.org/pdfs/control_guidelines/Equine%20Herpes%20Virus.pdfBecause there are many causes for abortions in mares, I would recommend having your vet come out and do an examination, including a culture examination, of her reproductive tract. This could help eliminate issues that could be spread to your other mares. Hope this helps!

I, honestly, am not at all familiar with the care of pregnant mares.But this sounds like something you need to discuss with a vet.

You said your mares get yearly vaccinations in spring, but every breeder I know vaccinates against Rhinopneumonitis 3 times during pregnancy to prevent abortion and other problems with foals that aren't aborted. I'd speak to your vet about this.http://www.aaep.org/ehv.htm