Prepare and monitor your expectant mare

While most pregnancies go smoothly, it helps to know how to monitor and manage your mare in the last months of pregnancy to reduce problems from developing.

Managing your expectant mare's diet, exercise and stress

Diet

You can treat your mare like any other horse until the last trimester of pregnancy (from 8 months) when most of the foal’s growth occurs.
Over-conditioning or overfeeding your mare can lead to health issues such as metabolic diseases and laminitis.
A diet designed for a pregnant mare is ideal because it’s balanced with appropriate energy, vitamins and minerals. Your mare should also have free access to quality forage.
You can monitor if her diet is adequate with body condition scoring.

Exercise

When to stop riding your pregnant mare is debatable.
Generally, you can treat your mare like any other horse for the first 6 months of pregnancy with light work and non-strenuous training that doesn't put your mare and foal at risk.

Stress

Your mare should not be moved in the last six weeks prior to foaling as this can lead to stress and bring on early foaling.
She needs enough time to build immunity and pass antibodies onto her foal in colostrum against infectious bodies in your local area.

Vaccinations and deworming for pregnant mares

Make sure your pregnant mare’s vaccinations are current, particularly for Strangles, Tetanus (Equivac 2-in-1) and Hendra virus.
Booster vaccinations should be given one month prior to foaling to increase antibody levels in the mare’s colostrum and help protect the newborn foal.
If Equine Herpes Virus (EHV) is a risk on your property, your mare should be vaccinated against EHV-1 and EHV[1]4 strains.
Make sure your mare is up-to-date with her deworming protocol especially in the last two weeks of pregnancy so she doesn’t infect her foal with worms.

Monitoring your mare during late pregnancy

It is crucial to monitor your mare daily, and twice daily in the last few months of pregnancy.

It is not unusual for a late term pregnant mare to be sluggish, eat less and generally be less energetic.
She may also develop swelling under her belly, which is normal.
Generally, reduce any stress in the last few weeks of pregnancy. If she has a caslick in place, get your veterinarian to remove it close to foaling.
Ensure you check her vulva, mammary glands and general demeanour.

Early signs of abortion

Mares can occasionally abort due to placentitis (infection of the placenta), viral diseases (such as Equine Herpes virus), carrying twins or uncommonly, processionary caterpillars.
Early signs of abortion can include: early mammary development, running milk, vulval discharge or signs consistent with foaling. Or she may show no signs at all. Contact your vet immediately if you are concerned.
If you mare does abort ensure you keep the foetus, membranes and mare separate from all other horses and contact your vet.

Signs of impending foaling

The average length of a mare’s pregnancy is 345 days but there can be a wide variation in normal from 320 to 380 days. Normally, an individual mare will have a similar pregnancy length every time.

Changes to expect

There are typical changes in the mare as foaling becomes close:

Her mammary glands begin to enlarge (two to four weeks pre-foaling)
Wax will appear on the teats (one to four days pre-foaling).
Her vulva will become softer and longer and the muscles of her croup will soften and flatten.

Predicting foaling

Changes in milk electrolytes and pH may help predict foaling but depending on the test this can be unreliable and testing can be difficult.
Monitoring for these changes is important but how close they are to foaling can vary.
Predicting foaling to the day can often be challenging, and using foaling alarms close to the mare’s due date is recommended.

It is always a good idea to monitor your mare’s foaling, as things can go wrong in a matter of minutes.