Mare Gestation Calculator & Chart | Calculate Foal Due Date (2024)

FAQs

Mare Gestation Calculator & Chart | Calculate Foal Due Date? ›

The average length of gestation for horses is 320 – 360 days. Use the calculator below to get the date 340 days from her last service/or the date she ovulated. Your pregnant mare should be vaccinated for tetanus (Equivac T) approximately 30 days prior to her due date.

The average length of gestation for horses is 320 – 360 days. Use the calculator below to get the date 340 days from her last service/or the date she ovulated. Your pregnant mare should be vaccinated for tetanus (Equivac T) approximately 30 days prior to her due date.

In one study, 65.5% of mares foaled at night between 8 p.m. and 1 a.m. The visual signs of a mare's readiness to foal are: Udder distension begins 2–6 weeks prior to foaling. Relaxation of the muscles of the croup 7–19 days prior to foaling; relaxation around the tail head, buttocks, and lips of the vulva.

Up to date from start to finish

The Filium App is a tool that takes you from the very beginning, in which the vet starts with the checking and scanning of the mare, until the due date on which you can expect your foal.

The average range of gestation is between 320 and 370 days. 340 or 341 days are accepted as the most common foaling days, but they are not a “due date”, merely an average of the average.

An estimated due date can be calculated by following steps 1 through 3: First, determine the first day of your last menstrual period. Next, count back 3 calendar months from that date. Lastly, add 1 year and 7 days to that date.

Typically, equine pregnancy ranges from 330-345 days. Length of the equine pregnancy is extremely variable, although many mares will have a similar gestational length in subsequent pregnancies. Mares can go significantly over their due date and produce a healthy foal; however less than 330 days is considered premature.

Mares will generally foal after an 11-month gestation, but this is highly variable. Studies have shown a range of gestation from 315 to 387 days, with an average of about 341 days. There is evidence that smaller breeds tend to have shorter gestation periods.

The pregnant mare may control, to a limited degree, the specific time that foaling occurs (i.e. foaling may be delayed slightly if the mare is stressed or disturbed). The average normal gestation length for an equine pregnancy is 340 days, with a range from 320 to 360 days.

Mares tend to foal late at night or early in the morning–the most tranquil time of day with the least intrusions. In the wild, mares typically give birth when it is dark to hide their vulnerable foals for the few hours it takes them to become physically able to rise and flee from predators.

Is there a free app for horse pregnancy? ›

My Foals is a simple and free app for a simple but useful task : enter the name of your mares and the dates of coverings, and the app will calculate the foaling window and the days left to 320 days.

After about six months, the mare may appear visibly pregnant. Over the remaining months, the mare's abdomen will continue to grow as the foal approaches the foaling, or due date. About three to six weeks before the due date, the mare's udder will start to expand.

Ultrasound Scanning

The first scan is performed on day 14 -15 after ovulation (16 – 17 post covering). It is the most reliable method of detecting twin pregnancies. Two scans are required between 14 – 18 days following ovulation if the mare has double ovulated.

The dates that are calculated are an estimate of when to expect your new arrival and should not be interpreted as an exact foaling date. This Foaling Date Estimator is based on 340 days gestation. You should average plus or minus 10 days for actual foaling window.

The normal gestation length for a mare is 342 days, however this can vary considerably and can range from 315 to 400 days. It is certainly not uncommon for mares to carry their foals beyond 12 months of gestation.

During this period, the mare undergoes a series of cycles, each approximately 22 days in length. The estrous cycle is divided into two physiological parts: estrus and diestrus. The estrus, or "heat" segment of the cycle, is three to seven days in length and is the time when a mare is receptive to the stallion.

With a drop of 0.5°C or more, there's a greater than 95% chance the a mare will foal within the next 12 hours. However, not all mares follow this pattern.

The estimated due date (EDD or EDC) is the date that spontaneous onset of labor is expected to occur. The due date may be estimated by adding 280 days ( 9 months and 7 days) to the first day of the last menstrual period (LMP). This is the method used by "pregnancy wheels".