Technology Saves Sleep Before Foaling

Unless you are a true night owl, foaling watch is tough. Even a few nights can ruin the best disposition, especially if you’ve got a day job. Worse yet, Murphy’s Law operates in full force during foaling, and many a mare has foaled while her attendant took a catnap.

The first improvement over camping out in the barn was video camera monitoring. This spared the mare the annoyance of someone hovering over her (or, worse yet, “foaling parties”) and allowed the observer a greater degree of comfort. But it didn’t solve the problem of lost sleep. Fortunately, we now have better options, the simplest of which is monitoring the mare’s temperature.

Temperature Changes
The horse’s body temperature fluctuates during the day (circadian variation), being lowest in the morning and peaking in the afternoon. A Cornell University study showed that the late-day increase in temperature did not occur in mares on the day prior to delivery. Mares foaling between 3 and 11 p.m., which is when most mares foal, showed a drop in body temperature prior to delivery. Mares that foaled both earlier and later than those times also had a tendency to show a drop in temperature before foaling, although it was not as significant.

This study also showed mares have an elevated body temperature after foaling before returning to normal. This “fever” can have multiple causes — exertion, tissue trauma, exposure to infectious organisms — but should clear up on its own.

Changes In Milk Chemistry
Another fairly simple method for predicting foaling arose from the observation that calcium and magnesium in the mare’s milk rise dramatically in late pregnancy.

The test uses the same reagents as hard-water test kits, either in liquid form or impregnated onto reagent strips. Collected secretions from the mare’s udder are checked for their “hardness”/calcium and magnesium content. Once you have mastered the technique for doing this (see sidebar), it’s a snap.

Using a tiny 1cc syringe, 0.6 cc of milk is drawn up and then diluted with 6 cc of distilled water — 1.5 cc milk and 9 cc water for FoalWatch ($24.95/20 tests). Distilled means the minerals are removed — no other type of water can be used. Spring/tap water contains calcium, which will throw off the test, and boiling water only concentrates the minerals. The diluted milk is then mixed with the testing solution. After waiting one minute, the calcium/magnesium level is read by either a color change in the indicating solution or on strips.

When using Predict-A-Foal ($43.95/15 tests), if there is no color change, or up to a 2+ color change (below 200 ppm on FoalWatch), you can relax. Odds that the mare will foal in the next two to three days are 10% or less. Wait a few days before retesting. When a color change enter the 3+ (200 ppm on FoalWatch) region, the odds are now around 40% (50% for FoalWatch). The more rapid the change to 3+ occurs, the closer she is to the 40% mark. At this point, milk changes can occur rapidly, so perform the test daily.

By doing the test late in the evening, your results should be the most accurate in terms of estimating what she is likely to do overnight. There’s probably no need to watch the mare overnight when you get 3+ readings (only 40% chance of foaling in next 12 hours). When the test changes to 4+ (200 to 300 ppm on FoalWatch), you now have an 80% chance the mare will foal in the next 12 hours. The more rapidly the test changes, the closer you are to that 80% chance. This is the time to begin watching the mare at night. If a rapid 5+ change (300 to 500 ppm on FoalWatch) occurs, get ready. There is now a 90+% chance this is the night.

The system works well. False negatives (no or little reactivity, but mare foals anyway) may occur if the test is performed with cold reagents (perform the test at room temperature with milk, water and strips/solutions at room temperature), with mares delivering prematurely (before 320 days), or in malnourished mares who are not producing adequate milk. Fescue toxicity may also interfere with the accuracy of milk tests.

If you get 4 to 5+ readings without foaling for longer than 24 hours, we suggest getting the vet in for an exam to make sure there is not a physical problem. If she is leaking/running milk, you need to collect at least a liter of it in case her colostrum is gone by the time the mare foals.

If she checks out OK physically, hang blankets over barred areas of the stall to increase her sense of seclusion (or move the mare to a private stall), keep light and noise in the area to a bare minimum, keep all other animals as far away from her as possible and meticulously clean the stall using lots of fresh bedding the last thing at night.

Both Predict-A-Foal and FoalWatch come with detailed, easy-to-understand instruction booklets. All measuring and mixing in the Predict-A-Foal is done by hand and eye, using graduations on syringes and test tubes or counting drops from a dropper. It was also easier to differentiate between a mare that was probably at least three days away from foaling with Predict-A-Foal, thus getting another good night’s sleep.

With FoalWatch, a self-filling titret is used for adding the test solution. The titret is supposed to lead to greater precision than counting drops. While it may have been a result of lack of familiarity with using the pipette (it did improve somewhat with practice), we found it difficult to assemble and to be certain it was drawing properly. The ampule, titret and filling chamber assembly were also difficult to line up properly.

There also was a problem with excessive air bubbles being created when using the titret. When reading the test, bubbles were always evident, and when you let the mixture sit for a few minutes they would settle out, giving a somewhat different reading than the one at the one-minute mark.

We did repeat tests on the same milk sample using both kits to see how much error there might be between results. The same sample of milk was used in each of the repeat tests, but we started at step one each time — with drawing up and diluting the milk. With the Predict-A-Foal, identical results were obtained each time. With FoalWatch, a difference of 50 to 100 ppm was not uncommon and probably resulted from the technical difficulty of using this kit (see above). These differences did not significantly influence our interpretation of the test, except in the 200 to 300 range where a higher reading on FoalWatch than Predict-A-Foal could cost you a night’s sleep.

Electronic Monitors
Electronic foaling monitors are designed to detect either that the mare is lying down flat (external monitors) or that the foal has entered or is about to enter the vaginal canal (internal/invasive monitors — see sidebar, below).

All electronic systems consist of three basic parts: a sensing device affixed to the mare in some way; a transmitter; and a receiver that may be either a pager or an alarm box. Various options are available including setups for monitoring multiple mares at the same time, adaptations that increase the detection range of the system, and relays that will dial a phone as the alarm method. Both position-sensing devices can also be used to monitor colic cases. We had two external foaling monitors, the Birth Alarm and Breeder Alert.

The Birth Alarm ($1,160) system has the sensor and transmitter mounted on a surcingle. The surcingle fits securely yet comfortably just behind the elbow despite the pregnancy. We found the craftsmanship and quality of materials/leather in this product to be excellent. Some assembly is required, but instructions are clear and assembly is minimal (necessary tools are provided). It took us about 25 minutes. The detection range is 150 to 200 feet. Intervening metal objects are the most likely to interfere. Ours transmitted through a solid stone wall in the barn to the alarm box that we placed on a window sill closest to the barn.

The system is activated if the mare lies completely flat for more than a few seconds. Researchers have determined mares in late pregnancy rarely rest in this position. There is also an optional setting on the device to allow for mares that continue to lie down flat to sleep. One mare we tested commonly laid flat to sleep, but after placing the device she found it more comfortable to remain in a sternal position or to rest standing.

Although false alarms are still possible with this system, we found it functioned beautifully on our test mares. We had no false alarms from mares lying down that were not in labor, even with the settings in the standard detection (seven seconds triggering the alarm). The alarms did not sound until the mare was in hard labor. By the time we arrived, the foal was emerging. We believe the design of the surcingle, with the stiff upper portion and anti-cast design, discourages mare from lying flat until the intensity of labor forces them to assume this position.

Bottom Line
For the ultimate in monitoring, electronic monitors are a godsend. While none of the devices are perfect — external monitors are prone to false alarms and unable to detect mares attempting to foal standing or with severe malpositioning of the foal — they are a big improvement. However, the cost is significant, especially for the one-foal breeder.

We recommend milk-testing kits as an effective and cost-efficient way to narrow intensive nightly monitoring to about three days or less. Our choice for milk-test kits is Predict-A-Foal, despite its heftier price.

Also With This Article
Click here to view “Indoor vs. Outdoor Foaling.”
Click here to view “Physical Signs.”
Click here to view “Is A Caslick’s Necessary'”
Click here to view “Anticipated Foaling Date.”
Click here to view “Collecting Milk For Testing.”
Click here to view “Do-It-Yourself Milk Testing.”
Click here to view “Internal Foaling Monitors.”
Click here to view “Breeder Alert.”

What did you think of this article?

Thank you for your feedback!