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So, your mare is pregnant. What do you do now?

Whether you wanted it or not, sometimes babies happen. Some owners try for years to get their mares pregnant, other mares are accidentally bred by your neighbor’s escaped stallion. There’s a lot to know when you find your mare (and self!) expecting!

My mare accidentally got bred, but I can’t handle a baby….

That’s okay. Just breath, then pick up the phone and call us! This is a pretty common scenario and easily remedied. Just like in people, there are medications comparable to the “morning after pill.” These medications will re-start your mare’s reproductive cycle to keep any possible embryo from implanting in her uterus. Keep in mind that not all mares respond to the first dose, so two doses may be recommended to ensure it works!

When should I get my mare checked for pregnancy?

  • Day ~14: The earliest day a pregnancy can be detected, via ultrasound.

  • Day 18-21: If ultrasound is not available, a pregnancy can be recognized on rectal palpation during this time.

  • Day 35: This day is a critical time of the horse’s pregnancy, as this is when the embryo final begins to implant into the uterus (up until now, it’s been rolling around like a marble). If a mare has twins, and the desire is to save one of them, but abort the other, it is most easily accomplished before this date.

  • Day 40: Most abortions occur in the initial stages of pregnancy, so it’s a good idea to get her rechecked around this day.

  • Day 55-70: A foal’s sex can sometimes be determined between days these days.

What if my mare has twins? Unlike many other species, twins are usually disastrous in horses, and it is extremely rare to hear of two completely healthy foals surviving into adulthood. The reason for this is that the mare’s uterus is not built to accommodate two foals, especially if both embryos implant into one uterine horn. A vast majority of twin pregnancies result in abortion of one or both of the fetuses, and sometimes pregnancy complications in the mare, such as “natural” abortions later in the pregnancy are often further complicated by retention of the placenta, which can lead to death if not properly addressed. Due to the high risk nature of twin pregnancies, it is better to abort at least one of the embryos – this creates the best odds that a live, healthy foal will be born in the end.

What does my mare need during her pregnancy? ​​Vaccines: There are several vaccines that your mare needs to both help maintain her pregnancy, as well as give your foal the best odds of survival. The important thing to remember is that the colostrum (the thick substance in the initial milk produced) contains antibodies that the mare has created to combat various different diseases that she has been exposed to, either in her environment or through vaccines. When foals are born, they have no natural antibodies, so it is extremely important that they receive as high quality colostrum as possible to help keep them healthy until they start creating their own.

  • Before breeding: Booster on all annual vaccines

  • Month 5: Equine herpes virus -1

  • Month 7: Equine herpes virus-1

  • Month 9: Equine herpes virus-1

  • Month 10: Booster on all annual vaccines (do not use any that are not explicitly labeled as safe for

  • pregnant mares). *These boosters are what increase the antibody content in the colostrum!*

Feed: You do not need to increase your mare’s caloric intake until about month 8 of the pregnancy, at which time, you should add on a feed specific to pregnant/lactating mares. Remember that once the foal is born and begins nursing, he more or less turns into a parasite, and sometimes the mare often keeps him fully nourished at the cost of her own body condition. Because of this it is preferable that your mare goes into foaling slightly heavier than average (only slightly!), as this gives her a little more wiggle room when she’s having difficulty keeping up with her milk production. Also keep in mind that as she nears the end of her pregnancy, her appetite may begin to go down. The foal takes up a lot of room in her abdomen, which often leaves little for her large colon, which is the organ that usually holds a large volume of food. The main food you should avoid during pregnancy? Fescue grass, as this often contains an endophyte that causes decreased or lack of milk production, prolonged gestation, dystocia (due to too-large foals), and placental problems.

What should I be watching for when her due date is nearing? There are several signs you can watch for as the due date is approaching, although no mare goes

completely “by the book.” If your mare has foaled before, keep in mind how things progressed

during her last pregnancy, as this is the best indicator of how this pregnancy will progress.

Due date: Mares usually foal between days 335-345 of pregnancy. Foals born before day 320 are

​considered premature, and usually do not survive. Some mares may remain in foal beyond a year!

This is uncommon, but often does not result in any problems with the foal. It is usually best to leave

nature to its own course, as the foal usually comes when it is ready! If you have specific concerns, do

not hesitate to call your veterinarian, though!

Udder: The udder begins to “bag up” slightly around 4-6 weeks before foaling and dramatically

enlarges within the last 2-3 weeks before foaling. The mare may begin to “wax up” within 24-48 hours

of birth – this is when colostrum begins to leak from the teat. A little is normal, but if she is leaking large volumes, it is best to catch this in a clean container and save it in the refrigerator. Do not attempt to milk anything from the udder before foaling, as this will waste valuable colostrum. The mare only creates a small amount of colostrum, and once the colostrum is gone, there is no getting it back!

Pelvic ligaments and vulva: Look at these now so that you know what “normal” is for your horse. Within 24-48 hours of foaling, the ligaments around the tail head and the vulva begin to sag as the mare’s body readies itself for foaling. Although these changes can be subtle, they are often one of your best helpers to know when the foal is coming!

When your mare seems to be nearing her due date, begin preparing a nice, clean environment for her to foal in. Clean, grassy pasture is usually the best, but if this is not possible, clean and disinfect (as much as possible) a stall, and line the floor with straw. A certain type of umbilical infection is associated with shavings, so it is best to avoid using this during foaling.

What happens during foaling?

The first thing you may notice is your mare becoming uncomfortable. These signs are often mistaken for colic, so take any potential colic episode seriously. There are certain serious forms of colic that are associated with late stages of pregnancy, foaling, and the days following foaling. Once your mare finds a good spot, the “water” will break. This is when the placenta ruptures and releases the fluid inside. Uncomplicated foaling usually occurs within 15-20 minutes of the water breaking. The first thing you will see are the front feet, followed by the head. Once these are out, the rest of the body should progress relatively easily. When the foal is completely out, it should be breathing, and the mare will begin to clean him. Within 2 hours of foaling, the foal should be up an nursing well. Within 3 hours of foaling, the mare should have passed the entire placenta.​​​​​​​​​

Call a veterinarian immediately if you notice any problems! Unfortunately, foals only have about 45-60 minutes from the water breaking to survive, so if you are noticing any problems within the first 15 minutes, call your vet immediately. Depending on the problem, they may be able to provide further advice until they arrive.

With all of that said, foaling usually goes well. Once you realize your mare is foaling, find a good spot to watch her from afar. Don’t try to help her unless there appears to be a serious problem. Horses are flight animals, so if everything is going well, you unfortunately will most likely be more of an annoyance to her than a help.

I think there’s a problem during foaling… What should I do? Your first step should ALWAYS be to call your vet! Any time wasted is extremely valuable, so before you do anything, call your vet!!

  • If the foaling is taking more than 20 minutes, there may be a problem.

  • If you see a velvety, red material coming from the vulva, this is called “red bag,” and is very serious. There are two halves of the placenta – the part that surrounds the foal, and the part that is attached directly to the mare’s entire uterus. “Red bag” is when the mare’s portion prematurely separates from the uterus. This can be problematic for both the foal and the mare, so once again, call your vet immediately. The foal cannot usually break though this, so they will advise you how to gently and carefully open this so that the foal can come out.

  • If the placenta around the foal does not break once he is on the ground, you can carefully break it open over its nose so that it can breath. This is usually able to be accomplished with your hands. Be extremely careful not to injure the foal if you need to employ any tools to break open a very thick placenta!

  • If you notice large amounts of bleeding during foaling, call your vet immediately. The fluids surrounding foaling are usually just red-tainted, but otherwise relatively clear.​​​​​​​​​

There is a relatively easy 1-2-3 rule of foaling:

  1. The foal should be completely out within 1 hour (although, as noted above 15-20 minutes is your vet-calling-cut-off-time!).

  2. The foal should be up and nursing well within 2 hours. Make sure they are latching onto the teat well.

  3. The placenta should be out completely within 3 hours. Save the placenta in a bucket or plastic bag for your vet to check when they visit your foal later.

If any of these steps does not occur, call your vet immediately.

There’s a baby in my barn. What do I do with it? Once your foal is born, if everything appears to be going well, call your vet to come out for a “new foal exam.” These exams are best done during 18-24 hours after foaling. Your vet will check your foal for congenital defects and any signs of illness, and will instruct you on how to monitor to foal for problems common to newborn foals. They will also draw blood to check your foal’s IgG level, which is one of the antibodies contained in colostrum. Low antibody levels are highly associated with foal illness or death, so your vet will make recommendations on how to best treat your foal. As long as your foal is nursing well and appears healthy, we won’t need to see it again until around 5-6 months of age, when it will receive its first vaccines. At this time you can also castrate your colt.

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