If a mare has one stillborn, is it more likely to happen again?

[MoonlightsMom]

There is a pregnant mare at one of the farms I work at, and she was due about a week ago. According to her owner, last year she carried the baby two weeks past her due date and it was stillborn. As of last night, the mare is still not showing any strong signs of going into labor anytime soon.

I don’t know much about breeding/broodmares, and I know her owner is already stressed about maresy, so I figured I would ask here instead of possibly stressing her owner out more. Is the mare more likely to have another stillborn after having one last year? Is it normal for mares to carry their babies weeks past their due date? If so, at what point does it become worrisome? Is there anything the vets can do to induce labor like doctors can for people?

Also, I know that if momma goes into labor while Im there I have a list of experienced locals to call. At least one of the people on the list should be within 15 minutes of the farm. While waiting for them to show up, is there anything I should/shouldn’t do? I was thinking after calling everyone I need to, just watch the mare so if needed I can describe what all was going on in case there was any sort of problem/abnormality. Am I thinking along the right lines?

[clint]

Was a necropsy done on the stillborn foal? It is hard to say if it is likely to happen again if you don’t know why it happened last year. As far as due dates, mares don’t have them. They have a range, from 320 to 360 days, with 340 being the mid-point of when a foal may be born.

Did the mare have a dystocia with the foaling resulting in the stillborn foal? A normal foaling takes about 20 minutes, so your thinking of being there so you can observe is good. There is a lot involved for a foaling attendant, and if your role is to call experienced help when she begins labor, be sure the owner has provided the things needed for the mare and foal.

[Didi]

I don’t know about the chances of another stillborn - I’ll leave that to the professional breeders to answer. As for when the mare begins to foal, if you are there the best thing you can do is NOTHING except call the experienced people you mentioned. Most of the time births proceed normally and as nature intended. Interference can stress the mare and cause more problems than it solves. If you think something looks off, keep the experienced people or a vet on the phone as they are driving to your area and describe what is going on. They can advise you of what, if anything, you should do. There are many, many good articles on the birth process on the Internet if you want to read up on it. Good luck!

[camohn]

Depends on why. In most cases can’t tell that for sure. Sometimes there is an obvious external reason… Umbilical cord torsion, lack of oxygen from red bag delivery, obvious deformity. Many times it is infection related, which cannot be determined without necropsy being done. Most common cause is rhinovirus exposure. All in all most causes are not likely to be repeated in a mare that has a clean culture and is utd on vaccinations. As to being a week overdue: means nothing. Due dates are an estimate. I have had them go to 365, some people more

[Kerole]

dystocia = foal was not positioned well and did not come out easily.

Yes, just sit and observe and describe what’s going on to the experienced locals.

The only thing I’d add, is to have a sharp knife or pointy scissors on you. You most probably will never have to use them but if you do, you won’t have time to run around trying to find them!

[rodawn]

Unless you knew what happened the first time around, there is no way to answer the question. If the foal was exposed to placentitis and was born dead due to the infection, then yes there is a greater chance placentitis causing even late term or full term abortion is possible, because mares who get placentitis once have a much higher likelihood of getting it repeatedly (although not always). If the death was due to a genetic anomaly, then again who is to say. There could have been a dozen or more reasons why the mare aborted her stillborn foal - and yes, this was likely an abortion at term. The foal likely died while in utero well prior to the delivery.

The average gestation time for horses is actually between 320 days to 370. The most common date is around 340 days. The longest recorded gestation is 445 days with a live foal delivery - according to Jos Mottershead. Mares have quite often carried their pregnancies long past the one year mark and it was not necessarily due to fescue problems or some other issue. They just kept carrying. Interestingly, those foals that born after a prolonged gestation actually tend to be quite small as a result of some delayed intrauterine development.