Even experienced breeders can miss some of the signs of pregnancy problems. Be sure you know you know your mare well, and report any questionable changes to your vet.

Whether it’s your first foal or you’ve been in the business over 50 years, as the clock winds down toward foaling day, the anticipation rises. You wouldn’t be normal if you didn’t find yourself worrying about the mare and how awful it would be if something went wrong at the 11th hour.  What would you do? How can you prevent this from happening to your mare?

Heavily pregnant mares tend to be subdued (or grouchy) anyway, and often don’t move around too much, so it can be difficult to tell if they’re feeling well. Having a system for monitoring them keeps you organized and makes the job much easier. Red flags mean at least a telephone call to your veterinarian is in order.

Appettite
Going off feed is always a good indicator that a horse isn’t feeling up to par but is common in later pregnancy. The large uterus crowds the digestive tract, often leading to mares eating less. There may also be some direct discomfort from the weight of the uterus and the fetus or from early contractions as the uterus prepares for delivery.

There’s no need to panic if the mare doesn’t clean up her grain, or skips a meal entirely, although you should always give her a quick check for red-flag signs. This will sometimes go on for a few days before she spontaneously goes back on full feed. During periods of poor appetite, monitor water consumption closely (this should not drop) and be careful to observe how much hay she is eating and/or if she is actively grazing.

Red flags are:

Mare also stops drinking and eating hay or grass.

Mare is also showing obvious signs of colic/abdominal pain.

Manure production is greatly decreased or absent.

Weight
It’s easy to lose sight of the body condition of the mare when she has a big belly, especially under a winter coat. Weight loss can occur quickly in late pregnancy if calorie intake isn’t adequate.

Train yourself to feel for ribs and along the top line. Keep an eye on her neck and shoulders for weight loss. You want to keep your mare around a body condition score of 6 throughout pregnancy and foaling, so that she has adequate energy stores to support the beginning of lactation/milk production.

Lameness
All the extra weight puts considerable strain on any joint, tendon or ligament problems the mare may have. Be sure to keep an eye on these areas and ask your vet for management tips if you think anything is bothering her. In general, unless she is having an acute flare up of a problem it’s best to make sure the mare spends as much time outside the barn as possible since gentle exercise is beneficial.

Pregnancy can also be a high-risk time for laminitis, which may be associated with a degree of insulin resistance that pregnancy induces. Ask your farrier to keep an eye out for white line stretching and sole dropping.

Red flags of foot pain are:

Greatly decreased spontaneous movement, mare rooted in place.

Obvious hesitation to move off from a standstill.

Reluctance to make tight turns.

Stiff, stilted “walking on eggshells” gait that’s worse on hard than soft surfaces.

Increased warmth in the feet, strong pulses in the digital arteries—can be felt running over the back of the fetlock joint.

If you suspect laminitis, don’t wait to act. It’s not going to go away on its own. Dietary changes can help.

Edema
Stocking up behind is fairly common in late pregnancy, probably the result of the heavy uterus compressing veins or lymphatics draining the back legs. Pockets of edema also commonly develop in front of the udder, even along the whole belly and extending as far forward as the chest. This resolves quickly after foaling. Less commonly, edema can also be a sign of viral infection that could threaten the pregnancy.

Red flags that the edema may be something more serious include:

Fever.

Edema of all four legs, not just the hind.

Nasal or ocular discharge, or change in breathing.

Problems with Pregnancy
Uterine torsion is a twisting of the uterus in a clockwise or counterclockwise direction. Picture the cervix as fixed in place and the uterus twisting around it. The cause isn’t always clear but may occur when the mare rolls or gets up from lying down, or possibly as a result of the foal moving.

Severe uterine torsions may require surgery, while milder cases can be corrected by deliberately rolling the mare (a maneuver for a vet), or may correct on their own. Red flags are:

Obvious colic/abdominal pain, often without change in gut sounds or manure production.

Colic that responds to pain relievers but returns.

Mare attempting to roll.

Late abortion (delivery before 300 days) or premature delivery may be caused by viral infections (equine herpes virus or equine viral arteritis) or, most commonly, by placentitis, an inflammation of the placenta that may be bacterial or fungal. Less commonly, toxins may be involved.

Red flags are:

Premature development of the udder.

Dripping milk.

Vaginal discharge.

Any of the red-flag signs warrant an immediate call to your vet, and probably an exam. Even potentially serious problems with the pregnancy can be treated and successfully resolved in many cases if caught early.

Bottom Line
Systematic, daily monitoring is your best defense, and it should include at least:

Observe for changes in attitude or personality.

Monitor water consumption and appetite.

Monitor manure production for changes in amount or consistency.

Daily check on the udder.

Check the vaginal area, and undersurface of the tail in contact with it, for any signs of discharge.

Run your hands over all four legs and the feet, checking for any swelling or increased warmth.

Observe for any signs of discomfort when walking, or decreased activity when turned out.

Body condition scoring every week or two.