Caring for the pregnant mare
A mare’s estimated foaling date can be calculated by adding approximately 342 days – around 11 months and one week – to her ovulation date.
However, this is only an estimate, as every mare has her own natural gestation length. A normal pregnancy may last anywhere from approximately 320 to 370 days. Previous foaling records can be helpful because individual mares often follow a similar pattern from one pregnancy to the next.
The estimated date should therefore be treated as a guide, and the mare should be monitored carefully as she approaches her expected foaling window.
Vaccinations and worming during pregnancy
A suitable vaccination and parasite-control programme helps protect the mare during pregnancy and supports the transfer of antibodies to the foal through her colostrum.
The precise programme should be discussed with your veterinary surgeon, as it will depend on the mare’s vaccination history, health, environment and level of risk.
Equine influenza and tetanus
The mare’s routine equine influenza and tetanus vaccinations should remain up to date throughout pregnancy.
A booster may be recommended approximately four to six weeks before the expected foaling date. This helps increase the concentration of antibodies in the mare’s colostrum, providing the newborn foal with important early protection.
Equine herpesvirus
Vaccination against equine herpesvirus – particularly EHV-1 – is commonly recommended during months five, seven and nine of pregnancy to reduce the risk of EHV-associated abortion.
Vaccination should be combined with appropriate biosecurity because it cannot eliminate every risk associated with equine herpesvirus.
Rotavirus
Rotavirus vaccination may be recommended during months eight, nine and ten of pregnancy. It can be particularly important on larger studs or premises with a previous history of rotavirus-related diarrhoea in foals.
The antibodies produced by the mare are transferred to the foal through her colostrum, helping to reduce the risk or severity of disease.
Worming
Pregnant mares should follow a responsible, targeted parasite-control programme advised by their vet. This may include faecal worm egg counts, tapeworm testing and treatment with a suitable product when required.
In some cases, an ivermectin-based wormer may be recommended during the final month of pregnancy to help reduce the transmission of the intestinal threadworm Strongyloides westeri, which can pass to the foal through the mare’s milk.
Not every worming product is appropriate at every stage of pregnancy. Always check the label and consult your vet before treating a pregnant mare.
Diet during pregnancy
The mare’s nutritional needs increase during the final trimester because this is when most foetal growth takes place.
Gradually increase the mare’s energy and protein intake during the final three months, according to her body condition and individual requirements.
Avoid underfeeding, as an inadequate diet may compromise the health of both the mare and her developing foal.
Take equal care not to overfeed. Obesity can place unnecessary strain on the mare and may increase the risk of complications around foaling.
Provide an appropriately balanced diet containing sufficient vitamins and minerals rather than simply increasing calories.
Ensure the mare has constant access to fresh water and suitable good-quality forage.
Make any dietary changes gradually to reduce the risk of digestive disturbance.
Regularly assess the mare’s weight and body condition. Your vet or a qualified equine nutritionist can help you formulate an appropriate feeding programme.
Dental examinations should be performed at least once a year, with treatment carried out when necessary. Good dental health is essential if the mare is to chew and digest her feed effectively and meet the increased nutritional demands of pregnancy.
Preparation for foaling
Ideally, the mare should be moved to her intended foaling environment approximately one month before her expected due date.
This gives her time to settle into the surroundings and develop antibodies against the organisms present within that particular environment. These antibodies can then be passed to her foal through the colostrum.
Moving the mare well in advance also helps to minimise the stress associated with a last-minute change of routine.
If the mare will foal indoors:
Provide a large, clean and secure stable.
Use a deep bed of clean straw. Straw is often preferred because fine shavings can stick to the wet newborn foal and its umbilical area.
Remove or securely cover any hooks, sharp edges, buckets or other potential hazards.
Ensure the stable is well ventilated without being draughty.
Provide clean drinking water for the mare.
Make sure there is good lighting in case veterinary assistance is required.
Have safe access to the stable and sufficient space around the mare.
A clean, secure paddock may also be suitable for foaling, but the unpredictable British weather means that a dry and sheltered alternative should always be available.
Consider installing a foaling camera or alarm so the mare can be monitored without being disturbed. Technology should support, rather than replace, regular physical checks.
Preparing a foaling kit
Prepare your foaling kit well in advance and keep it in a clean, easily accessible location.
Useful items may include:
Your vet’s routine and emergency telephone numbers
A clean headcollar and lead rope
A bright torch with spare batteries
Disposable gloves
A clean tail bandage
Plenty of clean towels
A clean bucket with a lid or strong bag in which to keep the placenta for veterinary examination
A clean thermometer
A watch, clock or phone for accurately recording timings
A notebook and pen
A charged mobile phone
A clean feeding bottle and suitable teat, if advised by your vet
An appropriate antiseptic solution for the umbilical stump, as recommended by your vet
Additional items such as sterile lubricant, an enema or foaling ropes should only be kept and used following veterinary instruction. Incorrect intervention can seriously injure the mare or foal.
Do not pull the foal, cut the umbilical cord or administer medication or an enema unless specifically instructed to do so by your vet.
Caslick’s procedure
If your mare has had a Caslick’s procedure, the vulva must be reopened before foaling. This helps prevent severe tearing and allows the foal to pass safely through the birth canal.
The procedure is commonly carried out approximately two to four weeks before the expected foaling date. Your vet will advise on the most appropriate timing for your mare.
If you are unsure whether your mare has a Caslick’s in place, ask your vet to examine her well before her due date.
Other considerations
Shoes: Your vet and farrier may recommend removing the mare’s hind shoes before foaling to reduce the risk of injury if she accidentally steps on or kicks the foal. This should be assessed on an individual basis, particularly if the mare requires remedial shoeing.
Exercise: Appropriate daily turnout is usually beneficial during an uncomplicated pregnancy. If turnout is unavailable, regular in-hand walking may be suitable.
Routine: Keep feeding, management and handling routines as consistent as possible and avoid unnecessary stress, particularly during late pregnancy.
Biosecurity: Keep pregnant mares separate from newly arrived horses, youngstock and horses that travel frequently to competitions or other venues.
Monitoring: Observe the mare daily and become familiar with her normal appetite, behaviour, temperature and physical appearance.
Emergency planning: Make sure everyone involved knows when and how to contact the vet. Consider how emergency transport would be arranged if the mare or foal required hospital care.
When to call your vet during pregnancy
Contact your vet promptly if you notice any unusual physical or behavioural changes during pregnancy.
Premature udder development
Some udder development is expected during the final two to six weeks of pregnancy, although the precise timing varies between mares. Maiden mares may show very little development before foaling.
Udder development or milk production significantly earlier than expected can be associated with placentitis, impending abortion or premature delivery and should be investigated.
Vulval discharge
Any abnormal discharge from the vulva during pregnancy should be reported to your vet.
It may indicate:
Infection within the genital tract
Infection or inflammation of the placenta, known as placentitis
Impending abortion
Premature delivery
Make a note of the discharge’s colour, consistency, odour and quantity, but do not delay contacting your vet.
Loss of colostrum
During late pregnancy, the mare produces her first milk, known as colostrum. This is rich in antibodies and provides the newborn foal with vital protection during its first months of life.
Foals are born with very limited immunity and must consume sufficient good-quality colostrum soon after birth.
If the mare begins dripping or running milk before foaling, she may lose a significant quantity of this valuable colostrum. Contact your vet promptly. The mare may require investigation, and plans may need to be made to provide the foal with an alternative source of antibodies after birth.
Do not attempt to milk or collect colostrum without veterinary guidance.
Ventral oedema
Some swelling beneath the abdomen can occur during late pregnancy. This usually extends from the udder towards the lowest part of the abdomen.
Contact your vet if the swelling:
Appears suddenly
Becomes extensive or increasingly severe
Is painful, hot or uneven
Is accompanied by lameness, reluctance to move or changes in behaviour
Is associated with any change in the position or appearance of the udder
Severe swelling or pain may require investigation to rule out problems such as an abdominal-wall injury, hernia or prepubic tendon damage.
Colic or changes in behaviour
Contact your vet if the mare develops signs of colic, becomes unusually quiet or distressed, stops eating, repeatedly lies down or displays any other concerning change in behaviour.
Abortion
If your mare aborts:
Keep her separate from all other horses.
Prevent other horses from accessing the foetus, placenta, fluids or contaminated bedding.
Contact your vet immediately.
Wear disposable gloves when handling potentially contaminated material.
Keep the foetus and placenta safely contained for veterinary examination, if your vet advises you to do so.
Avoid moving horses on or off the premises until you have received veterinary advice.
Veterinary investigation can help identify why the abortion occurred and determine whether an infectious disease may place other horses at risk.
This information provides general guidance and is not a substitute for advice from your veterinary surgeon. Every mare and pregnancy is different, so please contact us to discuss an individual vaccination, parasite-control and foaling plan.