What You Need To Know About Mares In Heat?

It’s good to have a mare as your riding horse because with a mare you not only have a good horse for yourself now, but you also have the potential of raising a colt from your favorite horse in the future if you so desire.

One of the drawbacks of riding a mare is that you must deal with her heat or menstruation cycle. This can pose some unique challenges. If you do not have plans to breed your mare and you don’t want to deal with her heat cycle, you may wish to consider riding a gelding instead.

In this article, we address questions regarding estrus cycle in mares and provide smart tips to help you decide whether or not you want to deal with it, and if so, exactly how you’ll go about it. Read on to learn more.

Mares In Heat Q&A

how often do mares come in heat

Why is a mare’s estrus cycle problematic?

When your mare is in heat, her behavior is affected by her hormones. She may be actively looking for mate during her estrus cycle, and conversely she will be attractive to any stallions or jacks who may be in your neighborhood.

This can pose some real safety hazards when riding or handling your mare.

How can you tell when your mare is in heat?

Estrus may bring about a number of different signs and symptoms in mares. You must watch for all of them, even though they may not all manifest at once. In fact, your mare may only have one or two indicators from time to time.

Watch for:

  • Difficulty handling or riding your mare
  • High interest in stallions or jacks
  • Standing in a breeding stance
  • Unpredictable behavior
  • Aggressive behavior
  • Lethargic behavior
  • Frequent urination
  • Loose droppings
  • Touch sensitivity
  • Tail raising
  • Squealing
  • Irritability
  • Anxiety

If you need to know absolutely whether or not your mare is in heat, you can call on your veterinarian to perform an ultrasound. This will give you certain information.

Use of an ultrasound is a good tool if you are actively planning to breed your mare. Your vet can perform the procedure to pinpoint the exact time when breeding is likely to be successful.

How often do mares come into heat?

A mare’s heat cycle is termed polyestrous. This means that throughout the warmer seasons (spring and summer) will have a heat cycle, but in the cooler seasons (fall and winter) she will not.

Typically the estrus cycle is brought on by light exposure. This means that in the springtime as the days get longer, your mare’s estrus cycle will begin. This will continue through the summer months. In the autumn, when the days become shorter, her estrus cycle will wind down.

How old is a mare at the time of her first heat cycle?

You can expect your mare’s estrus cycles to begin when she is about a-year-old. Mares typically do not become too old to menstruate, so expect heat cycles to continue as long as the animal lives.

How long are mares in heat?

Your mare’s estrus cycle will be about 21 days. This does not mean that she will be in heat for the entire time, though. Instead, during this time there will be about a week when you must be extra careful not to allow your mare to be bred, unless that is what you want.

Once her active heat cycle is over, there will be a couple of weeks when she is not in heat.

Be sure to take note of this on your calendar or using some other tracking method so that you will be able to predict your mare’s heat cycle in future.

When it is clear that your mare is not in heat anymore, count off fourteen days (two weeks). At the end of this time, your mare will likely go into heat again.

How do you deal with a mare in heat?

  • Make good plans. You should keep a record of your mare’s estrus cycle. This will allow you to plan important riding events and training. Keep track of your mares estrus cycles; keep a list of goals and objectives for horseback riding every month and come up with a plan that will work around your mare in heat.
  • Maintain strong boundaries. If you don’t want to breed your mare, you must be very sure that she is well contained during her estrus cycle to prevent accidental breeding. A mare who struggles to escape her enclosure in search of a mate may hurt herself. Poor fencing can also allow adventurous stallions and jacks to enter your property and access your mare.
  • Engage your veterinarian. If your mares estrus symptoms are extreme, talk with your vet about getting some pain medications for her. Alternately, there may be supplements that can be helpful to her.
  • Control her cycle. It is unfortunate that many big equestrian events take place in the summertime when many mares are in heat. When this is the case, you may be able to delay your horse’s estrus cycle by using medications such as progesterone.

Your veterinarian may be able to deliver this medication by injection. It works by tricking the mare’s body into thinking that she is already pregnant, much like birth control pills.

In this way, you can sidestep the symptoms of a mare in heat. Additionally, the use of progesterone will prevent your mare from being attractive to stallions.

Is progesterone safe?

Progesterone can make your mare more anxious and more irritable. How she would behave using progesterone is dependent upon exactly what sort of response she would normally have toward pregnancy.

Additionally, it’s important that you understand that repeated use of progesterone could cause your mare to become infertile. Progesterone is not the only option, and you can talk with your veterinarian about other possibilities for delaying your mare’s estrus cycle.

Is it dangerous to ride a mare in heat?

how do you deal with a mare in heat

No matter how gentle or well-trained your horse is, her hormones will override those tendencies. Reproduction is a very strong drive in horses and other animals, and it can cause your mare to become quite unpredictable and potentially dangerous.

Generally speaking, you may notice that your mare becomes quite irritable for periods of a week at a time during the spring and summer and then returns to normal for the following two weeks.

Again, you should keep track of this so that you can predict the periods and avoid riding, training and competition during this time.

In the wintertime, you will not need to worry about your mare going into heat because this simply is very unlikely to happen during the cold, short days of fall and winter.

When your mare is in heat avoid the following activities:

  • Don’t sneak up on your horse. This is never a good idea, but it is especially a bad idea when your mare is in heat. Always say her name and make sure she knows that you are there before approaching her from the rear.
  • Take care when brushing and grooming around the flanks and rump. Your mare may be irritable and may not want to be handled in these sensitive areas.
  • Avoid making your mare irritable, and don’t punish her if she is. She can’t help it, so you should simply try to stay on her good side and give her some space. Use techniques such as redirection to distract your mare from her irritability. Plan quiet activities or even a period of complete rest during her estrus.
  • Be patient. During the week when your mare is in heat, lower your training, riding and performance expectations. To continue to push your horse to perform during this time is quite stressful for her. During the week when your mare is in heat, you can work on things such as groundwork or simply give your mare a break.
  • As with all conditions, a mare who is healthy and strong will be able to handle estrus better than one who is underfed or poorly kept. Always strive to keep your mare happy and healthy and to develop a strong relationship with her so that she trusts you even when she is stressed.
  • If your mare is very irritable during her estrus. Are very unpredictable, you’ll need to work with your veterinarian and perhaps with a professional trainer to get her behaviors under control. Remember that safety is always the most important consideration.


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