The Stables

That Time Of The Month…


Over the years, mares have developed a reputation for being difficult while they’re in season, but the key to getting the best out of mare is to be adaptable and sympathetic in your stable management and training regimes – particularly while she is in season.  Some people do seem to naturally ‘click’ with mares. They tend to respond best to sensitive, understanding handlers . There is truth in the old saying, ‘You tell a gelding and ask a mare’?

The behavioural changes that occur in a mare when she is in season are caused by the mare’s natural drive to breed which  can overrides her willingness to co-operate being ridden or handled. Most girls and women will understand how rotten the mare could feel – imagine if you have rotten PMT or tummy ache and someone asked you to clamber around an assault course!


In season cycles

Mares are seasonally polyoestrous, which means that they only come into season during the spring, summer and autumn. Pregnancy in horses lasts approximately 11 months, so the break in her cycle during winter ensures that the mare doesn’t give birth to a foal when the weather is at its worst. The mare’s cycles are controlled by hormones, which respond to the changes in the duration of daylight, so once the days get shorter leading into winter, the mare stops cycling.

Regardless of whether you plan to breed your mare, her heat cycles will affect her–and subsequently you. In order to better understand and care for your mare, you need to understand her heat cycles as the last thing a horse owner wants is for heat cycles to interfere with riding and training and horse safety.

Mares typically cycle regularly between April and early September. For a few months on either side of that, the ovaries are in the process of either gearing up for spring or slowing down for winter and may produce one or multiple follicles at irregular times. During these spring and autumn transition periods, the mare may or may not show signs of being in season. Reproductive behaviour is most likely to be noticed during the fertile period between April and September.

A mare’s cycle is shorter than a woman’s. The average length is three weeks, with most falling within the range of 18- to 23-day cycles. The mare will be in season or ‘show heat’ for an average of five days during each cycle, with a range of three to seven or eight days. The normal cycle is for the mare to be in season for the better part of a week, followed by two weeks out, then another week or so in.


How can you tell when a mare is in season?

Typical signs that your mare is in season include holding the tail elevated, “winking” (opening and closing) the lips of the vulva and variable amounts of squatting and squirting of urine and mucus. A mare’s level of activity may slow down and she can seem preoccupied, quite frankly you’re not the most important thing on her mind! These signs of full-blown “heat,” will intensify gradually over a few days, then stop abruptly after she ovulates.

Just before coming into season, and often for the first few days of her season some mares can be very irritable and sensitive to touch. They may threaten to kick or even bite. Part of this is because the hormonal changes are making her focus elsewhere so that she is more easily startled. Pressure-like pain from the enlarging follicle and/or pulsations in the ducts that will carry the egg to the uterus are causing her pain.

Some mares can become extremely difficult to manage when they are coming into season; others never exhibit any signs at all. In fact riders who have experienced the best that mares can offer wouldn’t have anything else.


Ughhh PMT!

If your mare is suffering with her season you may see some, or all of the following signs:-


Easily distracted


Oversensitive – hates being groomed, tacked up or touched.


Unwilling to work/Poor performance

Excessive flirting

Low-grade colic

Repeated urination

Change in energy levels


Handling moody, hormonal behaviour in mares

First of all, you need to make sure that your mare has a true hormonal problem.  If your mare’s behaviour is changing every three weeks for four to six days at a time, it would suggest that her hormones are to blame.  Write a diary of your mare’s behaviour so that you can see whether there’s a pattern. If she’s fine during the winter and you discover that her behaviour falls in a three-weekly pattern during the spring, summer and autumn – you can be fairly certain that her hormones are the cause.



If your mare shows irritability and touchiness just before going into season, you may have to adjust your handling of her during those times.  However it is ok to send a strong message when you’re in the saddle or actively leading her to tell her “OK, it’s work time” and remind her to focus on you. Consider focus-type lessons, such as ground poles and changes of speed and direction or if that fails just a hack out may be what is needed.

When handling never approach her from behind, unless you’re sure she has noticed you are there.

Start grooming her at the neck and shoulder, working your way back to the more sensitive flank regions.

If the irritability is extreme and could be dangerous your vet can give you something to help her with pain relief.  The vet will undoubtedly examine her to make sure her ovaries are normal before prescribing any treatment.

Some people with problem mares use the drug Regumate. This is a progesterone that mimics the hormonal profile of a pregnancy so the mare doesn’t show in season. It eliminates problems that interfere with work, but  actually doesn’t do a thing for irritability or touchiness, and may actually make that worse. Elevated progesterone mimics the hormonal profile during human PMS.


Managing the situation

If your mare gets hormonal, there’s not much you can do to prevent it, but there are some things you could try to help ease the situation:-

Try keeping mares in a separate field away from geldings, so that your mare isn’t pestered by the geldings and she can’t flirt with them. This will also help to avoid any potential injuries caused by unwanted advances.

Some owners find that herbal supplements help – Chaste berry has been found to be effective in balancing hormones.

Camomile is useful for cramps, calming and relieving pain.

Vervain is said to relieve tension and is good for horses who are sensitive about being touched.

Remember to check the ingredients of your herbal supplement if you compete, as some herbs are banned in competition.

Give your mare a few days off work while the worst of her behaviour passes. If she’s being difficult, riding won’t be enjoyable for either of you!


Article via Lavender & White Publishing

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