How Long Can A Horse Be Pregnant?

How long does horse stay pregnant until it gives birth?

  • Though a horse is generally pregnant for 10-11 months, they still may give birth to a healthy foal before or after that time. It is important to provide your mare adequate care during this time to ensure a healthy foal. Please comment if you enjoyed this article or have any remarks regarding this article!

What is the longest a horse has been pregnant?

When are they due to foal? The ‘average’ gestation for horses is 340 days, but ‘normal’ gestation can be as short as 320 days and as long as 370 days. The longest recorded successful gestation was 445 days, although most foals born after an extended gestation are small in size due to delayed uterine development.

How many months is a horse pregnant for?

Normal mares have a broad range of gestation. It is very normal for mares to carry a fetus for 320 to 380 days. In general 330 days ( 11 months ) is the most commonly cited gestation length.

Can a 30 year old horse get pregnant?

Mares can continue to produce foals well into their late teens or early to mid 20’s. However, mare owners should realize that the prognosis for fertility of an older mare decreases each year.

How long is too long for a mare to be pregnant?

For horse breeds, alas, gestational periods of mares are far more variable, with anywhere between 320 and 370 days completely within normal limits. Some experts extend this range further, indicating a 380-day gestation could be considered normal. Multiple studies have evaluated gestation lengths in mare herds.

How long can a mare carry a dead foal?

What is abortion? Abortion is the delivery of a dead foal and its placenta before an age at which the foal would have been able to survive independently. This is usually taken to be up to day 300-310 of gestation. After 300-310 days, if a dead foal is delivered it is usually termed stillborn.

How many days can a mare go over her due date?

So a mare that goes over significantly ( more than 30 days ) over her due date may have some placental dysfunction resulting in slower maturation of the fetus and a delay in foaling.

Which animal is pregnant the longest?

Elephants have the longest pregnancy period of any living mammal. If you – or someone you know – has experienced a pregnancy that seemed to go on forever, spare a thought for the elephant. It’s the animal with one of the longest gestation periods of all living mammals: nearly two years.

How many horses can a horse have at once?

How Many Foals Can a Mare Have at Once? Mares typically give birth to one foal per pregnancy. On very rare occasions, she can have twins. However, the odds of a successful birth of twins are very slim because there’s very little space for two foals to grow in the uterus.

How long is a horse in labor?

The foal is usually born after 12 to 18 minutes of heavy labor. Maiden mares (mares foaling for the first time) are more likely to take about an hour to expel the fetus. Handlers should be ready to assist if it goes much longer than an hour. Mature mares in labor for more than 30 to 45 minutes may also need assistance.

How long does a horse live?

Most horses have a seasonal breeding cycle, going into heat for the first time of the season in early Spring and ending in late Summer. Mares go into heat every 21 days during this breeding season and are fertile and receptive to mating during 5-7 days out of their cycles.

How old was the oldest horse ever?

The oldest horse ever was called Old Billy, who was foaled in Woolston, Lancashire in 1760, and was 62 years old when he died on November 27, 1822.

How overdue can a horse go?

Mares commonly have gestation lengths longer than the average of 335-340 days, and this is a common concern to horse owners. Usually, there is no cause for worry. Gestation can be as long as 375 days and the record gestation length is over 400 days.

Can a horse be pregnant for 12 months?

Average Gestation Period The gestation period in horses is typically between 330 and 345 days, or 11 months. 1 Some mares will be inclined to foal earlier or later than the average, and breeders will get to know these tendencies. Ponies usually have a shorter gestation period than horses.

Can you use a home pregnancy test on a horse?

The Wee-Foal-Checker test kit. A revolutionary $30 do-it-yourself pregnancy test for mares delivers a result within 10 minutes, its New Zealand developers say.

How Long Is a Horse Pregnant?

How long does it take a horse to become pregnant? Well, the quick answer is 10 to 12 months, or around 326 to 354 days, depending on your perspective (although there have been cases where gestation for a mare has gone as long as 365 to 370 days). The majority of mares only give birth to one foal per pregnancy, while twins do occur on rare occasion. If you’re thinking of breeding your horse, there’s a lot more information you should be aware of. Mares are polyestrous on a seasonal basis. Put another way, it indicates that the mare behaves somewhat similarly to a cat in that she will go through numerous cycles throughout a specific season.

This is assumed to be an evolutionary trait to guarantee that the mare gives birth at the most favorable time of year, which is believed to be in the springtime.

The Mare’s Cycle is Key

A thorough understanding of a mare’s life cycle is essential for managing mares in general, and it is absolutely essential for designing a successful breeding program. Due to the fact that mares are seasonally polyestrous, the mare will respond to light stimulation. This implies that when the amount of daylight increases, her cycles will begin to begin by reducing melatonin levels. The following are crucial dates to keep in mind for horse breeders:

  • In the United States, the Summer Solstice is celebrated on June 21, which is the longest day of the year and the apex of the natural mating season. During the Fall Equinox, which occurs on September 21, when there is equal daylight and darkness, and the mares are shutting off as the season changes, Horses are in their deepest anestrus on December 21, which is the shortest day of the year and the shortest day of the year. The mares are in Spring Transition 1 during the time of the Spring Equinox, which occurs on March 21 when there is equal light and dark.

These are, of course, estimates based on current information. When it comes to the commencement of cyclicity, temperature can also play a role because it is thought to be regulated in part by a neurotransmitter that is also involved in prolactin release. The lowering of opioid inhibition of the gonadal axis may also have a role in the initiation of the breeding season, according to certain theories. Normal horse cycles are said to begin around the Summer Solstice, which coincides with the start of the natural mating season.

Those mares that are bred early in the year (typically during the first quarter) will often carry their foal for a longer period of time than anticipated.

2 In addition to these considerations, whether the foal is a colt or a filly is another aspect that may influence a mare’s gestational duration.

Body weight can also have an impact on gestation times; mares that are thinner have a tendency to bear their offspring for a longer amount of time than mares who are heavier.

Due to this, the mare will go into heat earlier in the year, which will result in the foal being born earlier in the year, which is typically a benefit for the owners and managers of performing breeds.

Gestation Stages

During their pregnancy, mares go through three trimesters, which are called trimesters. The first trimester begins with conception and is usually completed within two weeks of confirmation. 3 It is critical to have the mare examined by a veterinarian during the first trimester in order to safeguard her and her foal’s health throughout the whole pregnancy. When the foal is roughly 25 days old, the veterinarian can do an ultrasound to identify the foal’s heartbeat and establish that the foal is still alive.

  • If twins are discovered, the veterinarian may inquire as to whether the owner or management would be interested in having the second embryo removed in order to offer the surviving embryo a greater chance of survival.
  • A horse-like appearance may be recognized in the foal at three months by ultrasound testing; important characteristics can be identified, and the gender of the foal can be confirmed.
  • 3 In this period, the mare can begin receiving deworming and vaccination treatments.
  • The mare will begin to exhibit her abilities after six months.
  • At this point, it is necessary to increase the number of veterinarian visits once more.
  • As the mare approaches her due date, it is critical to maintain a pleasant and stress-free environment for her, avoiding any dramatic changes that might cause her to become worried.

Leading Up to Foaling

On average, the day of foaling should occur between days 326 and 354 of the calendar year. There are test kits available that some breeders use to assist them anticipate the day of foaling. These can be particularly beneficial if it is the mare’s first foal and the mare’s foaling procedure is unknown. 2 When it comes to the days leading up to delivery, the mare is likely to display signals that her body is preparing for childbirth. Her udder is likely to appear large, and she may even be dripping milk.

To ensure the mare’s comfort, a big stall with plenty of straw, fresh water, and hay should be supplied.

It is possible that she will get up and down a couple of times, but she will give birth while laying down.

2,3The amniotic sac will most likely be the first portion to be seen, followed by the head and legs of the developing baby. Once the amniotic sac is seen, it is usually just a matter of minutes until the horse is delivered. 3

Labor and Delivery

Approximately 85 percent of mares give birth at night, which is likely a survival strategy that permits the foal to be ready to run with the mother as soon as daylight appears. This will cause the mare to get agitated during the initial stage of labor. She may begin to kick at her stomach and engage in nesting behavior. A large number of mares sweat throughout the process of foaling, which is referred to as the mare “heating up.” Wrap the tail and thoroughly clean the perineal region. This period normally lasts around an hour and fifteen minutes.

  1. The foal’s front hooves, nose, ears, and other features should be revealed as the foal grows.
  2. This can be elicited by softly massaging the foal’s nostrils with a blunt item, such as a pencil.
  3. 3 Other recommendations and warnings include cleaning any biologics with iodine before using them.
  4. After delivery, some experts believe that a little amount of blood enters the foal through the umbilical artery, which is connected to the mother.
  5. According to the literature, if the placenta does not discharge within three hours, it should be considered an emergency needing the care of a veterinarian.
  6. The mare herself should not require any post-partum care in most cases.

Emergency Situations

The development of the amniotic sac as a “red bag” during the second stage of labor is one of the more prevalent complications during pregnancy and childbirth. The amnion (also known as the amniotic sac) is the first item to appear during a normal foaling. It is a white membrane that surrounds the foal. When the placenta separates from the uterine wall prematurely, blood will collect within the amnion, giving it a deep crimson look. This is an uncommon occurrence, but it does occur. This is a life-threatening emergency that might result in the foal’s death if not addressed immediately.

1 Eilts, B., et al., Equine Seasonal Cycle.

How Long Do Female Horses Stay Pregnant?

Johnson, Karen S. “How Long Are Female Horses Pregnant?” Animals –, November 21, 2017, accessed October 7, 2018. Pregnant Mare: Ensure the health and well-being of the mare when she is pregnant. The American Association of Equine Practitioners published a statement on October 7, 2018.

About NexGen Pharmaceuticals

NexGen Pharmaceuticals is an industry-leading veterinary compounding pharmacy that provides sterile and non-sterile compounding services to veterinarians in the United States and Canada. NexGen, in contrast to other veterinary compounding pharmacies, concentrates on pharmaceuticals that are difficult to locate, are no longer accessible owing to manufacturer discontinuance, or have not yet been commercially released for veterinary purposes, but which nonetheless fill an essential need for our clients.

  1. It is also urged that our pharmacists establish excellent working connections with our veterinarians in order to provide better treatment for our animal patients.
  2. Disclaimer The material provided in this blog post is of a general nature, and it is intended to be used solely as a source of information.
  3. Neither is the information intended to serve as medical advice or diagnosis for specific health problems, nor is it intended to be used in making an assessment of the risks and benefits of using a particular medication.
  4. The Food and Drug Administration (“FDA”) has not examined the information and assertions provided, and the FDA has not authorized the drugs for use in diagnosing, curing, or preventing illness in humans.
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What to Expect When Your Mare is Expecting

A few fundamentals of equine reproduction and pregnancy include mating, the gestation period, and foaling, among other things. In most cases, a mare (or female horse) can produce one viable foal every year on average. An adult mare is capable of delivering afoalat at the age of around 18 months, but it is healthier if the mare is at least four years old, since she will have grown to her maximum size by that time. A mare can produce offspring until she is in her late thirties, if she is in good health.

A veterinarian should always be present when horses mate and give birth, but many difficulties may be avoided by having the stallion tested before breeding, as well as having the mare assessed and cared for appropriately during the gestation time.

Average Gestation Period

When it comes to horses, the gestation period is normally between 330 and 345 days, or 11 months. A breeder’s ability to recognize if a mare is more likely to foal earlier or later than the norm is essential for success in the breeding industry. In a natural context, the stallion will breed the mare in the summer, and the foals will be born the next year, either in the spring or early summer of the following year. This guarantees that the foals are born when there is plenty of forage and the weather is moderate, which is ideal for raising them.

These seasonal estrus cycles occur typically every three weeks during the spring and summer.

Because of the artificial sunshine, the mare’s brain is stimulated, causing it to release the reproductive hormones necessary to induce estrus.

Checking For Pregnancy

Mares may not display any obvious indicators of pregnancy during the first three months of their pregnancy, other from the absence of an estrus cycle. Approximately two weeks after conception, a pregnancy can be verified with an ultrasound. Blood and urine tests can be performed two to three months following conception to confirm pregnancy. Alternative methods include rectal palpation, which allows a veterinarian to manually feel the small embryo in the mare’s uterus at approximately six weeks into the pregnancy, and sometimes even earlier.

Horse twins are extremely unusual, however they have been known to cause spontaneous abortions.

As a result, it is frequently suggested to “pinch off” one embryo at a time.

It is not uncommon for a mare to miscarry her pregnancy, and it is advised that she get an ultrasound and have her blood or urine tested again after around three months.

Later Stages of Gestation

After around three months, the foal will be growing fast and will begin to resemble a little horse. After around six months, the mare may begin to show signs of pregnancy. Mares that have already given birth may exhibit signs of an enlarged abdomen more quickly than a virgin mare. While still pregnant, the mare’s abdomen will continue to develop in size as the foal near the time of foaling or the due date for birth. The mare’s udder will begin to develop around three to six weeks before the due date, and the teats will begin to produce a sticky yellowish fluid a few days before the due date of the birth.

  • If the yellowish fluid is allowed to ferment, it will transform into the first milk or colostrum.
  • It is possible that her stomach will appear to lower as the foal aligns itself for delivery.
  • The mare will appear restless shortly before giving birth; she may paw the ground or continually glance toward her flank (hip) area on either side (similar tocolic symptoms).
  • The mare may lie down and rise up several times, but she will most likely give birth while lying down on the ground.
  • At this point, the foal is usually born within a few minutes after being conceived.
  • Sometimes a mare or foal gets damaged during the birthing process, or the mare or foal may be suffering from another problem that needs immediate or expert treatment.
  • This is a life-threatening situation that cannot be postponed (not even for the arrival of the vet).
  • The foal should be protected by this membrane.
  • The placenta is responsible for supplying the foal with oxygen, and if it is prematurely removed before the foal is able to breathe on its own, the foal will be deprived of this vital source of nutrition.
  • In such instances, every second matters, and the mare must be physically aided in the birth of the foal, and the’red bag’ must be burst as soon as possible to allow the foal to take its first breath.
  • If you have any reason to believe your pet is unwell, contact your veterinarian immediately.

Always consult your veterinarian for health-related inquiries, since they have evaluated your pet and are familiar with the pet’s medical history, and they can provide the most appropriate suggestions for your pet.

How Long Is a Horse Pregnant? (Symptoms & Stages)

In humans, pregnancy is always considered to be a fragile state, and there is no substantial difference between humans and animals. When it comes to horses, such an attitude is based on mares’ comparatively poor reproductive performance when compared to the performance of other domestic animals in the same environment. As a responsible owner, you can ensure that your mare’s pregnancy progresses as smoothly as possible by paying close attention to her and providing her with extra care. However, regardless of whether you produce these gorgeous creatures for pleasure or for show, the most important issue to ask is how long a horse may be pregnant for.

The Ideal Age for Breeding Mares

When a mare is 18 months old, she has the potential to get pregnant. The best age for breeding is still when the animal reaches the age of at least four years. Premature breeding can have negative repercussions for a mare’s health and well-being. As a result, it is preferable to wait until it has reached full maturity. Furthermore, there is no necessity to begin breeding too early, as female horses can get pregnant until they are in their late twenties.

Seasonal Polyestrous

The mare is a seasonal polyestrous mare, which means she has two periods each year. Although it may appear confusing, it simply implies that mares go into heat (estrus) only from the beginning of spring through the end of summer or the beginning of October. During this time, horses are sexually receptive and fertile every three weeks, and they are able to reproduce. The fact that the seasons have an effect on pregnancy makes tracking these cycles essential since it has an impact on the intended breeding.

Those who are conceived during the spring and summer, on the other hand, nearly generally have shorter pregnancies.

The thinner and smaller mare will be able to bear the foal for a longer period of time than the bigger mare.

How to get the mare into heat earlier and the foals to be born earlier in the year is accomplished in this manner.

Pregnancy Check

The lack of estrus is the first symptom that a woman is pregnant. The chances of your mare becoming pregnant are high if you have bred her and she has not gone into estrus within three weeks of breeding. You should be aware, however, that certain mares might display indications of estrus even after pregnancy, so you must use caution when breeding them. As early as two weeks after breeding, you may call a veterinarian to have your mare’s pregnancy confirmed by ultrasound. This is one of the most reliable methods.

Following conception, a blood and urine test are performed to determine whether or not a woman is pregnant.

Please keep in mind that because some mares do not exhibit any indications of pregnancy, it is conceivable that the owner will only discover the pregnancy a few hours before the scheduled delivery.

False pregnancies in horses, on the other hand, are prevalent, so you should pay close attention to your mare’s behavior. If it exhibits one or more of the typical indications, it is recommended to get it examined by a veterinarian.

Horse Pregnancy

The average length of a mare’s pregnancy is 320 to 380 days (10 to 11 months). As a result, a mare can only have one pregnancy each year due to these factors. It will go through three trimesters in all, about.

The first trimester

It all starts with fertilization, which may be confirmed by a veterinarian after two weeks. An ultrasound scan is performed around 26 days later, and the veterinarian can hear the foal’s heartbeat. He will also be able to tell you whether or not your horse is carrying twins. By the third month, the veterinarian will be able to confirm the gender of the foal.

The second trimester

It begins somewhere around day 114. As the foal grows fast during this stage, the mare will want more food and larger amounts in order to keep up with the growing foal.

The third trimester

Finally, this period will begin roughly 226 days after the conception of the child. It is critical to regularly check your mare’s health and to discontinue training her after the seventh month of her life. As the day of your horse’s birth approaches, it is critical that you avoid making any big changes because this can be stressful and upsetting for your horse.

Pregnant Horse Care

Many parts of your mare’s care will stay the same as they were before she became pregnant. Light physical exercise is recommended during the first month following conception since this phase is critical for the foal’s survival. Aside from that, mild training is one of the most effective methods of preparing your mare for birth. You can even ride your horse up until the sixth month of your pregnancy if you want to. You can resume this exercise as soon as your body has recovered after giving delivery.

During this time, most foals acquire a couple pounds every day on average.

During pregnancy, keep in mind that the mare is more susceptible to illness than usual.

Twin Pregnancy

In rare instances, a mare can get pregnant with twins, however the majority of the twins’ foals will not survive owing to difficulties. Once the veterinarian has determined that your mare is carrying twins, he or she can remove one of the embryos to give the other a better chance of survival. During the first two months of her pregnancy, a mare with twins has a 95 percent probability of rejecting one or both of the embryos she has produced. Delaying the next pregnancy by waiting for this to happen naturally is not a smart idea since it will prolong the next pregnancy.

If this is not done, foals will most likely be delivered early and with health problems. Despite the fact that multiple occurrences of mares giving birth to healthy twins have been documented, it is nevertheless recommended that you visit a veterinarian if this occurs.

Premature and Overdue Foal

It is unlikely that the foal will survive if it is born before the 300-day mark. The animal’s respiratory system, on the other hand, is not fully developed and will remain dysfunctional. Placentitis is a condition that might affect the mare from time to time. It results in a shortened pregnancy and a foal that is undeveloped and hence unlikely to survive. Veterinary hospitals frequently treat foals born between 300 and 320 days old that require neonatal critical care. The good news is that it will almost certainly live if you give high-quality upkeep.

  • In most cases, there will be no issues, save that it may be less than anticipated.
  • It is widespread in rural areas where mares graze on fescue pasture or are given fescue hay, as well as in certain urban areas.
  • As a result, it is suggested that it be removed from the mare’s diet two to three months before she gives birth to her foal.
  • Otherwise, most veterinarians would not perform this treatment since it poses a threat to the foal’s life and health, according to the ASPCA.

Labour and Delivery

In the wild, mares give birth to their foals at night in greater than 85 percent of cases. The explanation for this is most likely due to the amount of time a foal need to adjust to new settings until the morning. Be prepared for the mare to get disturbed during the initial stage of labor, refusing food and drink, walking in a circle, and alternatively lying down and standing up, among other things. There are three stages to the delivery process:


The mare’s tail should be wrapped to keep the perineal region clean. This is the most prolonged phase of the storm and can run anywhere from 30 minutes to six hours in duration. For older mares, the tail is normally shorter. This period will be completed after the mare’s water breaks.

Fetus expulsion

The second phase of labor is shorter than the first, however an upset mare might cause the delivery to be delayed for a brief period of time. As a result, you should keep noise levels to a bare minimum and avoid upsetting it. As soon as the contractions begin, the mare has the option of standing or lying down. When the birthing process begins, it will, however, be on its side. It takes around an hour for a firstborn mare to remove the fetus, but an older mare takes approximately 12 to 18 minutes.

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Afterbirth placenta delivering

While blood is still flowing via the umbilical cord, the mare will lie on her side for an additional 15 to 20 minutes following the delivery of her foal. As a result, it is suggested that you do not trim it immediately after giving birth. It is recommended that you avoid approaching the foal for the following several hours since they have a strong protective instinct and can be aggressive towards people if approached. After one hour, the foal should stand up and begin sucking.

After two hours, the foal should begin sucking. In most cases, the mare does not require postpartum care. Veterinary assistance is required if the placenta does not pass within three hours. The mare’s life is in risk if this does not happen.


A horse can be pregnant for up to eleven months in most cases. An otherwise healthy foal may be born to a mare before or after the scheduled delivery date. Under order to achieve a risk-free delivery and a healthy foal in such circumstances, it is important to give your mare with the right care.

How Long Are Female Horses Pregnant?

Photographs courtesy of IJupiterimages/ Images Your mare – female horse – is entering her 11th month of pregnancy with her four-legged foal. If you or someone you know has gone through a long human pregnancy, you will understand and have compassion for her. Horses have an average gestational period of 335 to 342 days, which is approximately 11 months.

Variations in Gestation Length

You shouldn’t be alarmed if your pregnant mare reaches the one-year mark without giving birth; 360 days, or slightly shy of one year, is still within the usual gestation length for horses. A preterm birth that happens a few weeks before her 11-month due date will not often be considered premature as long as she is healthy and the pregnancy has proceeded normally, says your veterinarian.

Deciding to Breed

It is important not to take breeding decisions carelessly. Make certain that both your mare and the stallion you choose have good characteristics. To determine when your horse is “in heat,” which is when she is receptive to the stallion or likely to become pregnant through artificial insemination, you’ll need to keep track of her reproductive cycles. If something goes wrong during the pregnancy or birth, you stand to lose time, money, and the lives of the mare and the kid.

Factors That Can Affect Gestation Length

In part because of seasonal factors, if you breed your mare during the months of February, March, or April such that she would be due in January through March of the following year, the odds are that she will carry her foal for approximately one week longer than if you breed her later in the year. References Resources Photographic Credits Writer Karen S. Johnson’s bio Karen S. Johnson is a marketing expert with more than 30 years of experience who specializes in business and equestrian issues.

Many of her writings have appeared in trade and business media, such as the Houston Chronicle, and she continues to write.

She graduated from the University of Texas in Austin with a Bachelor of Science in speech.

Understanding How Long Is A Horse Pregnant

Whether breeding for pleasure, performance, or show, every step of the breeding process is meticulously planned and thought out beforehand. To produce the greatest possible horse, a significant amount of time, money, study, and consideration are invested. With all of the effort that goes into breeding, you’ll be curious as to how long a horse is pregnant for.

A Typical Horse Gestation Period

From conception through birth, a horse’s gestation period is usually between 10 and 11 months. In most cases, mares only have one foal each pregnancy, while twins have been known to occur on rare instances. These factors contribute to the fact that a horse can only have one pregnancy per year and will normally only have one foal per year.

Horses can have a rather wide range of gestational ages. They can be pregnant for a period ranging from 320 to 380 days. In most cases, a horse is pregnant for 330 days, which is around 11 months.

How Long is a Horse Pregnant: Gestation Stages

During the course of her pregnancy, a mare will go through about three trimesters. The first trimester begins with conception and is usually completed within two weeks of confirmation. It is important to have your mare checked by a veterinarian throughout the first trimester in order to keep track of the health of both her and her foal. As early as 26 days, a veterinarian can do an ultrasound to discover the presence of a heartbeat and to determine the health of the animal. Your veterinarian will be examining the mare at this time to determine whether or not she is pregnant twins.

  1. |
  2. In this period, the mare can begin receiving deworming and vaccination treatments.
  3. The third trimester begins approximately around day 226 of the pregnancy.
  4. You should be able to consistently exercise your mare until approximately the seventh month.
  5. Avoid making any significant alterations since this may lead the mare to become agitated.

Horse Breeding Season

Horses are typically bred throughout the summer months in order to ensure a spring or early summer birth. This allows the foal to have access to fresh grass when it is ready and guarantees that the foal does not have to face the chilly winter temperatures at a young age when it is not ready. When it comes to breeding a horse, a lot of thought and effort goes into it.

Seasonal Polyestrous: Mare in Heat

Seasonal polyestrous horses may seem difficult, but it simply means that horses go into heat (estrus) more frequently throughout the spring and summer than during other seasons. When a horse is in heat, it indicates that they are both sexually responsive and fertile, which is a good sign. When it comes to the spring and summer, heat cycles usually occur every three weeks on average. Some breeders, particularly those who raise Thoroughbreds, may attempt to control a horse’s reproductive cycle in order to increase their profits.

This permits the foal to be born earlier in the year, which might be advantageous for racehorses who compete in early-season races.

How Long is a Horse Pregnant: Twins

It is possible for a horse to conceive twins, albeit this is unusual. Unfortunately, the majority of the time, both foals do not survive since horses’ bodies are not designed to bear two infants at the same time. When a mare carries twins to term, there are a number of difficulties that can arise for both the mother and the baby in the majority of cases. The majority of the time, twins are produced when a mare has ovulated twice, producing one egg from each ovary. In the case of a divided embryo, the formation of identical twins is extremely unlikely.

If twins are discovered, your veterinarian may choose to remove the second embryo in order to offer the other embryo a better chance of survival.

Only in rare instances may a mare give birth to healthy twins, and they are rare. However, if your mare is pregnant with twins, it is advisable to speak with your veterinarian to ensure that your mare has a good pregnancy.

How Long is a Horse Pregnant: The Most Exciting Part

In order to ensure that you are properly prepared for the arrival of the foal, you will need to continue monitoring your mare’s progress during the third trimester. When your mare reaches approximately day 315, you should be on the lookout for symptoms of pregnancy, since the foal will most likely arrive around day 330. In some cases, a mare bred early in the year may be able to carry her foal for an extra week, whereas a mare bred later on may be able to carry her foal for a shorter amount of time.|

Signs a Mare is About to Give Birth

Your horse will most likely exhibit indicators that she is ready to give birth in the days leading up to the delivery. Her udder will most likely appear large, and she may even begin to drop milk. During the preparations for the foal’s birth, herbelly will most likely appear to have collapsed. It is preferable to provide your mare with a big stall that is covered with straw and has access to freshwater and hay. This will provide the mare with a safe and pleasant environment in which to give birth.

It is possible that she will get up and down a couple of times, but she will give birth while laying down.

Once the amniotic sac is seen, it is usually just a matter of minutes until the horse is delivered.

A Beautiful New Life

When a foal is born, it is an extremely joyous moment. Generally speaking, a foal will be able to get up and walk around within an hour of being born. It will then be able to run around. The foal should be contentedly feeding within two hours after being born. When your mare goes into labor, it is usually a good idea to have your veterinarian there. After delivery, your veterinarian will be able to assist you with any problems that may arise and will be able to examine the health of the foal after it has been delivered.

Worth the Wait

A horse is usually pregnant for 10-11 months, although they can still give birth to a healthy foal earlier or beyond that period if they are in good health. It is critical to provide your mare with enough attention during this period in order to ensure a healthy foal is produced. Please leave a comment if you appreciated this post or if you have any questions or comments about this topic!

How long can a mare go past her due date?

This is an extremely significant question, since it has the potential to have several ramifications. If a mare carries her foal over her due date, her health, as well as the foal’s, may be jeopardized. Because of the restricted blood supply to her uterus, a mare who has gone over the due date of her pregnancy may experience placenta rupture. Additionally, they may experience issues with their foals, like as difficult deliveries, a retained placenta, and fetal distress. Because of the delayed uterine development, the majority of foals delivered after a protracted gestation are tiny in stature.

Mares will often gestate for somewhat more than 11 months, however gestation lengths as long as 380 days are still seen to be acceptable in some circles. The longest successful pregnancy that has been documented so far was 445 days.

How many babies can a horse have at once?

Horses are often only capable of bearing one child at a time. It is possible, though, that a mare will begin to produce more than one embryo at a time. In this instance, however, they will most likely terminate the fetus during the later stages of the pregnancy. Twin pregnancies in horses are generally considered to be exceedingly undesirable due to the fact that they nearly invariably result in a negative conclusion. It is common for foals to succumb to their injuries within 24 hours of birth, while mares can succumb to a number of ailments, including abortion and retained placenta.

How do you calculate a foaling date?

The expected delivery date may be calculated by taking the mating date and adding 338 days or 11 months to get the foaling date, which equals 11 months. If you wish to calculate the whole range of possible foaling days, follow the procedures below: for the earliest possible foaling, start with the mating date and add 331 days to the end of the calculation. Take the mating date and multiply it by 346 days to get the earliest potential foaling. Since it will be hard to estimate the exact date of foaling in the vast majority of cases, use those figures more as a guideline and pay close attention to your mare’s behavior and make certain that she has all she requires.

How can you tell how far along a horse is pregnant?

A rectal examination is required within three weeks of the mare’s covering in order to determine whether or not the mare is pregnant. In order to do a rectal examination, the veterinarian must insert his hand into the rectum in order to palpate the uterus and examine its size, shape, and the presence of any swelling in the ovaries. It is common for the uterus to seem larger and more rounded throughout the second trimester of pregnancy, as well as to have a solid consistency at this time period.

The veterinarian will palpate the abdomen, feel the fetus, and listen to the heart rate with a stethoscope to determine the status of the pregnancy.

Still Waiting for your Foal?

We’re all excited to meet the new arrivals! When do they expect to have a foal? Equine gestation lasts 340 days on average, however it can be as little as 320 days or as long as 370 days depending on the individual horse. The longest successful pregnancy ever documented was 445 days, however most foals delivered after such a lengthy gestation are modest in size due to the delayed growth of the foetus in the uterus. There are a variety of factors that influence the length of gestation, including the genetics of the foal and the time of year in which the foal is due.

  1. Keep in mind that the phrases ‘premature,’ ‘dysmature,’ and ‘postmature’ refer to the state of the foal at the time of delivery, not the length of the mother’s pregnancy.
  2. Pregnancies in miniature horses may be shorter than those in full-size horses, and foals born after gestations as brief as 280 days may be healthy.
  3. If you have a foal born between 300 and 320 days gestation, you run the danger of it being preterm and needing some form of critical care.
  4. There are no precise signs of approaching parturition that may be identified.
  5. The mare’s belly will become larger and pendulous throughout late pregnancy, although the abdomen may get smaller during the last week of pregnancy when the foal slides towards the birth canal.
  6. Approximately 4 weeks before parturition, the mare’s udder should begin to grow and fill with milk, with continuous expansion and filling of the teats occurring one week before parturition.
  7. The calcium content of the mare’s milk may be measured on a daily basis, and when it reaches 200 parts per million (ppm), the mare is on the verge of giving birth.

The mare may become restless or even colicky in the days leading up to giving birth to the foal. False labor is a possibility, but keep an eye on her since she is likely to reach the latter stages of labor very rapidly! Take pleasure in your new foal!

Gestation in Mares: What Is Premature? What Is Overdue?

The start of foaling season causes a great deal of anxiety among mare proprietors. It’s possible that some of the concern stems from a misunderstanding of what constitutes a normal gestational duration in horses. Mares, in contrast to many other animals, do not have a well defined gestation time. What a number of mare owners would do to have their animals be as reliable as sows, with their virtually failsafe pregnancy duration. Sows give birth between 114 and 118 days after breeding, accounting for more than 94 percent of all births.

  • Unfortunately, for horse breeds, the gestational durations of mares are significantly more varied, ranging anywhere between 320 and 370 days, which is entirely within acceptable bounds in most cases.
  • 2 Several studies have been conducted to determine the gestation durations of mare herds.
  • The average gestational duration for the 594 foals born as a consequence of these records was 349 days.
  • 3 In the field of animal husbandry, the terms “premature” and “dysmature” are sometimes considered to be identical.
  • Premature foals are those that are born too soon in relation to the duration of the gestational period.
  • The hair coats of foals in both circumstances may be smooth, and they may have curled ears, tiny bodies, domed heads, and slack tendons.
  • When is it too early to start?
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This is due in part to the fact that surfactants, which aid in the development of the respiratory system, do not function the same way they do in women.

Foals born between 300 and 320 days of age commonly require neonatal critical care, which is normally provided at a veterinary hospital.

Foals delivered after 370 days of gestation are normally healthy and do not show any problems, albeit some are smaller than expected as a result of the uterine development that has been delayed.

Prolonged gestation can be caused by endophyte-infected fescue poisoning.

Fescue poisoning can cause pregnancy to be prolonged, but it can also have additional consequences such as a thicker placenta and decreased milk supply.

4 Mare owners frequently inquire about the possibility of triggering labor in late mares.

It is essential to provide foaling mares with an energy-dense meal that has a comprehensive complement of vitamins and minerals in order to ensure their nutritional well-being.

For example, feeding mares marine-derived omega-3scan benefit them on a number of levels, as they can assist to boost immunological function, improve colostrum quality, promote passive transfer of antibodies, and raise conception rates*.

Ketchem and M.

The National Pork Producers Association (NHPA).

The American Association of Equine Practitioners is a professional organization dedicated to the care and treatment of horses.

Dicken, E.K. Gee, C.W. Rogers and I.G. Mayhew in 2012. The New Zealand Veterinary Journal, volume 60, pages 42-46. 4 McCue, P.M. (2009, 2009). Domperidone is a drug developed by Colorado State University.

Pregnancy, Mare is Overdue, Over 340 Days Pregnant

Observation What you see is what you get. Your observations should serve as the beginning step for resolving any horse health-related concern.


Equine owners are frequently concerned about mares having gestation durations that are greater than the norm of 335-340 days. In most cases, there is no need to be concerned. As long as 375 days pass between conception and delivery, with the longest pregnancy lasting more than 400 days. It goes without saying that a mare should exhibit indicators of pregnancy progressing in the latter weeks of her pregnancy. As she approaches her due date, her udder should be expanding and her belly should be pendulous, indicating that she is pregnant.

Code Yellow

Make an appointment with your veterinarian whenever it is most convenient for you.

  • It is recommended that you seek medical attention if you are concerned about the pregnancy or the mare and would like an assessment.

Code Green

Make an Appointment with Your Vet to Receive Helpful Advice Resources

  • Do you have any worries about the mare that is late in her pregnancy?

It’s possible that you’re also paying attention.

your role

When in doubt, use the Whole Horse Exam on Late-Term Mare (WHE) to check the mare’s overall health. Then call your veterinarian to discuss your results and any concerns you have. Keep an eye on the mare’s flanks and feel for any movement of the fetus. Squeezing a drop or two onto your palm every few days will allow you to keep an eye on the color of the fluid coming from the teats. As a mare gets closer to giving birth, the secretion will change from a clear, honey-colored liquid to one that resembles genuine milk.

Provide your veterinarian with all of these information.

What Not To Do

Just though a mare was pregnant during the early stages of pregnancy does not mean that she is still pregnant towards the end of the pregnancy.

Skills you may need

You may be required to conduct procedures on your horse at some point.

your vet’s role

Your veterinarian may urge you to adopt a “wait and see” attitude, or they may recommend that you get your mare examined. They may do a rectal examination as well as an abdominal ultrasound to assess the fetus and placenta over the course of the pregnancy. Questions Your Veterinarian Might Ask You:

  • In what condition is the mare’s udder and the region surrounding her tail head in appearance
  • What were the mare’s breeding seasons like? What is the mare’s attitude and appetite like? In what condition is the mare’s udder and the region surrounding her tail head in appearance
  • Who knows what the outcome of the Whole Horse Exam (WHE) will be.

Diagnostics Your Vet May Perform

Identifying and addressing the root source of the problem. These are tests or procedures that your veterinarian will use to discover what is wrong with you.

Diagnoses Your Vet May Consider

The underlying source of the problem. This is a list of diseases or ailments that are causing the observations that you are making.

Treatments Your Vet May Recommend

A method of resolving the issue or diagnosing the problem. Identifying and treating the underlying causes of disease or treating the symptoms of disease (symptomatic treatment)

further readingresources

Experts in horse health have written, reviewed, and shared their findings. Doug Thal, DVM, Dipl. ABVP is the author of this article.

Pregnant Mares: What owners need to know as foaling time approaches – Oklahoma State University

Tuesday, March 2, 2021 is a Tuesday. The use of moderate activity during a mare’s pregnancy, such as active walking or riding, will aid with controlling her weight and maintaining muscular tone and strength, which will be required during her final 2 1/2 months of pregnancies. Feed her a high-quality forage diet with the same quantities as before pregnancy, but with an increase in energy to meet the needs of pregnancy in order to preserve her bodily condition. When it’s chilly outside, take into account the additional requirements for keeping her body in good shape and increase her ration appropriately.

  • Establish a deworming program with your veterinarian that is both effective and safe.
  • Because infectious infections can cause abortions, it is important to get up-to-date vaccinations.
  • Increased antibody levels in the mare’s colostrum, which in turn helps to protect the newborn foal from illness, should be delivered one month before foaling for chosen vaccinations.
  • Remember, nature has created a marvelous system of birth in the mare, which you should take use of.
  • Mares, as opposed to cattle, have a lower incidence of problematic births than cattle.
  • The average duration of a mare’s pregnancy is 338 to 343 days.
  • Mares appear to have some control over their delivery and prefer to give birth in the seclusion of their own homes at night.

Your mare will require a clean, safe, and peaceful environment in which to give birth.

If not, she will want a stall that is spacious enough for her to lay down comfortably with space on both ends.

If a stall with a floor that can be easily cleaned and disinfected is available, utilize that one instead.

When it comes to bedding, fresh bright straw or fresh grass hay is preferred than shavings.

Additionally, wood shavings can be a source of pathogens and poisons in rare cases.

A number of factors can contribute to excessively protracted pregnancies, all of which should be examined.

The viability of the unborn foal may be determined by your veterinarian using ultrasound technology, just as it is with human newborns.

When a foal is born, it is critical that the foal nurse colostrum during the first 12 hours of its life.

Without sufficient colostrum, the foal is at higher risk of infection.

Additionally, the serum of the foal can be analyzed between 18 and 24 hours of age to determine IgG antibody levels.

If given before 24 hours of age, colostrum from a tested resident mare can make a significant difference in the foal’s survival. Here are some important factors to remember, as well as when to contact your veterinarian:

  • If your mare begins to produce milk before the 320th day of pregnancy, she is considered pre-mature. If your mare does not have a filling udder (colostrum) within one week of her due date, you should contact your veterinarian. If the mare produces milk regularly for more than three to four days before to foaling, the mare is considered pregnant. If severe labor (pushing) continues for more than 20 minutes without any indication of the foal erupting from the vulva, the foal is considered to be in distress. If the feet are presented with the soles up, the front feet and nose should be the first to be exhibited. A word of caution: Premature placental separation, sometimes known as “red bag,” need prompt medical intervention. Break (tear or securely cut) the bag extending from your mare’s vulva and covering the foal’s feet immediately if it is velvety red instead of milky white. Otherwise, the foal will suffocate within minutes if the bag is not broken or safely cut. Once the foal has been born, contact your doctor. If the placenta is not expelled within three to six hours of the baby’s birth, the baby will be born prematurely. The foal does not rise within one hour of birth, suckle within two to three hours of birth, or pass meconium (first stool) within one hour after rising and having an enema
  • This is considered a failure to thrive. To finish up, have your veterinarian examine the mare, the foal, and the placenta around 24 hours after the delivery to see if there are any symptoms of problems.

OSU’s College of Veterinary Medicine Ranch provides foaling services for owners who want a break from the stress or when nature takes a turn for the worst. This is a service that other North American veterinary institutions do not provide. Maternity mares and their unborn foals are monitored by senior clinicians and fourth-year veterinary students during the late stages of pregnancy, utilizing ultrasonography and udder secretions. During the last stages of the mare’s pregnancy, she is kept under 24-hour surveillance, which includes closed-circuit television, until her kid is born successfully.

Horse owners and the horse business in Oklahoma and the surrounding areas have found the ranch foaling program to be a highly useful instrument in the training of future veterinarians, as well as a vital resource for future veterinarians.

Oklahoma State University College of Veterinary Medicine |

a little about the author: G.

ACT, is a professor at the Oklahoma State University College of Veterinary Medicine and holds the Bullock Equine Reproduction Endowed Professorship, which he received from the Bullock family.

The professors of the Ohio State University Veterinary Medical Hospital contribute to Veterinary Viewpoints.

To schedule an appointment or for additional information, call 405-744-7000.

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