Hands up who’s had a mare with Jekyll and Hyde tendencies? Sometimes she’s sweetness and light but other times, she’s a teeth-baring monster. Yes, we’ve all had to manage a moody mare but help is at hand. Read on for our advice.

A mare’s behaviour can change (often in springtime), and this is can be due to a fluctuation in hormone levels, including oestrogen and progesterone.

Horses are seasonal breeders, programmed to mate at a certain time of year.

Over the winter months most mares are anoestrus, which means they’re not cycling.

As daylight hours increase, this acts as a stimulus for them to become reproductively active.

In early spring, as this change gets underway, mares enter a transitional phase.

They may have prolonged or erratic cycles as hormone levels adjust, and behaviour can become unpredictable.

This ‘mare-ishness’ will often subside by early summer, by which time most will be having regular three-week cycles.

Signs that your mare’s in season include tail raising, opening and closing of the vulva (winking), frequent posturing and urination.

However, some may also show more problematic behaviour. They may become vocal and anxious, display signs of aggression, be painful or sensitive around their flanks and reluctant to work.

Manage her moods

How you manage a moody mare depends on the individual – each horse’s behaviour will vary. In the majority of cases this will be solely linked to your horse’s seasons and there’s little you can do work around her mood swings.

However, this behaviour can be associated with other health problems, such as an ovarian tumour. It can also be unrelated to her reproductive tract and caused by something else, like musculoskeletal pain.

If your mare’s behaviour persists, it’s important to establish whether it’s associated with her reproductive tract or not, something your vet can assess by examining her.

Your vet might suggest a supplement to help regulate her mood swings or the following:

  • A progestogen called altrenogest, which is widely used in a veterinary product known as Regu-Mate. It works in a similar way to the human pill in that it stops the mare’s cycles, and it’s one option that can be very effective in a large number of horses.
  • The insertion of a sterile marble in through the cervix into the uterus. This tricks the mare’s body into believing she’s pregnant and this stops the cycles.
  • In a small number of cases, year-round aggressive behaviour, especially where the mare shows almost stallion-like behaviour, may be due to a granulosa cell tumour.

This is a benign tumour that produces a mix of hormones. It’s rare, but something your vet may well check for, especially if Regu-Mate or a marble insertion doesn’t solve the problem. A simple blood test can be taken to confirm the presence of this tumour.

Advice from holistic therapist Dena Schwartz

“Spring can be a challenging time for many mares – their hormones are racing and they have one thing they need to do and that’s procreate,” says holistic therapist Dena.

“In the wild mares would do exactly that and then spend the next 11 months blissfully pregnant.”

Dena advises that offering certain herbs and oils once or twice daily can help a moody/mareish mare. “Allow your mare to decide which ones she needs, and how much of each she needs, as allowing her to control the dosage will give the best results.

“Red clover and liquorice root help to normalise hormone function, chamomile flowers will help her to feel calm and ease any discomfort, and nettle leaf is a gentle uterine tonic.

“Next, add three drops of rose otto, three drops of geranium and three drops of vanilla extract into small separate bottles of passion flower oil. Offer each one for her to inhale or simply lick from your hand.

“Most importantly, be understanding and tolerant of your mare – hormones are powerful things and can affect all of us in extreme ways.”

Advice from behaviour expert Andrew Kerr Sutherland

“Common sense is key when you’re riding and handling an extremely hormonal mare,” adds behaviour expert Andrew Kerr Sutherland.

“You need to be conscious of your mare’s seasons and the fact she could suddenly become highly irritable as she comes into season; and be vigilant as to who she’s turned out with.

“Ideally she shouldn’t be around any males, especially a rig or stallion as this will make things 10 times worse. However, she also shouldn’t be turned out with a dominant mare as this can cause even more problems and could end up in a fight.

“Some mares can spring into season unexpectedly, so make sure your horse’s home life is as chilled as possible to help bring her cycles back into place. But bear in mind that this can take up to two years depending on the mare.”