If you own and/or ride a mare, you may notice a change in their behaviour when they are in season — perhaps you’d even describe their behaviour as ‘moody’ — and fortunately there are numerous supplements available to help relieve her symptoms.

I’m not a fan of the term ‘moody mare’. I think it’s unfair to dismiss a female affected by hormones she has no choice to deal with as being a behaviour issue. A change in behaviour could just as easily be caused by something else; discomfort around the tummy area is one sign of gastric ulcers, for example.

As responsible, caring horse owners it is our job to understand what is going on inside a mare’s body so that we have a better idea of what she is feeling and why. Some mares show little to no signs of being in season. I have owned and ridden several mares and none have been particularly ‘mareish’. However, others can become very uncomfortable. This might cause them to put their ears back when you’re trying to groom; feel ‘stuffy’ when you’re schooling, or even refusing a fence she’d otherwise jump with ease. So it’s easy to see why mares quickly earn the unfavourable tag of being ‘moody’.

“Many owners use the analogy of comparing a mare being in season and having to exercise as women doing sport when having a period,” says equine behaviourist Jenni Nellist. “Horses don’t have periods in the same way that women do, so it is different and you don’t want to anthropomorphise your horse too much. She could be frustrated or distracted during this time when she is driven to find a mate and so may pay less attention to you.”

Do you need a moody mare supplement?

A lot of unwanted mare behaviour is blamed on hormones, but, explains Jenni, there’s not a lot of scientific evidence to suggest that this is the case.

“In fact, recent research has demonstrated that abnormal mare behaviour is rarely associated with hormones,” she says. “Hormones that control oestrus make everything relax to make breeding easier. This is why some mares become more tactile or loving when in season. If you are seeing frustrating behaviours, this could stem from the fact that she’s not breeding. Frustration can cause stress, and that’s why you can see behaviours related to this. It is vital that you don’t put these behaviours down to hormones without veterinary investigations first, though, as they could be due to other underlying causes of discomfort.”

If you own a mare and you suspect she’s in season, it can be tempting to initially reach for moody mare supplements, but before this you should discuss any concerns with your vet.

“A vet will probably want to work through a process of elimination to see what’s going on,” explains Jenni, who is a member of the Association of Pet Behaviour Counsellors and Fellowship of Animal Behaviour Clinicians. “They can also look at hormone profiles and run tests as part of a clinical work up. Keep a diary of your mare’s behaviour to see if you notice any patterns. A mare’s season is typically 21 or 22 days  long. If it isn’t repeating within this cycle then it probably isn’t due to hormones. Remember that challenging behaviour is your horse trying to communicate with you — and you shouldn’t just assume that her behaviour is caused by hormones because she’s a mare.”

Key ingredients in moody mare supplements

If you decide that a supplement is needed for your mare, it is important to consider what ingredients it includes. Wheatgerm extract is thought to be useful in helping a mare cope with her symptoms. Its key ingredient has prebiotic-like functionality that optimises the gut flora balance, helping the body’s own mechanisms to regulate themselves. This in turn is thought to support mares who show signs of unwanted behaviour when they are in season.

A 2016 study by Weetman et al that was published in Veterinary Timesshows showed that wheatgerm extract had a statistically positive effect on behaviour such as kicking, biting, grumpiness, bucking, difficulty tacking up and poor performance in oestrus mares.

Mares supplemented with wheatgerm extract at the onset of oestrus showed significant improvements in her behaviour, some in as little as 12 hours and all by 36 to 48 hours. Conclusions were drawn that dietary supplementation with wheatgerm extract offers an effective solution to the frustrating problem of behavioural changes of mares in season.

Read the full study: ‘Supplementary control of oestrus behaviour in mares’

What is Regumate?

Most of the veterinary treatments available for mares in season are either hormonal or surgical. In terms of hormonal treatment, Regumate, which contains a progestagen, is used by vets to assess whether the sex hormones are to blame for the reported behavioural problems. Short courses of the drug will provide information but the behaviour is likely to return shortly after the drug is discontinued. Some owners use it long term but it is not licensed for use in this way and is very expensive.

Regumate differs to the range of ‘moody’ mare supplements you see for sale in tack stores as it can only be bought after being prescribed by a vet. It is a liquid that is given to horses directly into their mouth, or it can be added to a small amount of feed.

“Regumate is usually used to prevent the hormone-dependant behavioural changes associated with oestrus, or to control the timing of ovulation so that the timing of mating and birth can be organised,” says Viovet. “It can be given daily to a mare early in her season and usually within three days it will stop that oestrus. Regumate can continue to be given once daily afterwards to prevent the return to oestrus. When daily dosing stops, 95% of mares will show signs of returning to oestrus within 5 days.”

RRP £137.25 for 1 litre bottle or £48.99 for 150ml (US$152.95 for 1000ml)

Buying in the UK? Purchase here

Buying in the US? Purchase here

Shop for ‘moody’ mare supplements

NAF Five Star OestressNAF Five Star Oestress

Oestress Powder compliments the mare’s natural oestrus cycle by encouraging regularity and providing extracts of herbal ingredients that have been used for hundreds of years to support hormone balance. It also provides bio-available magnesium to relax muscle tension and encourage calmness. Being rich in natural antioxidants helps Oestress to naturally support a healthy system. This supplement should be fed daily throughout the spring and summer season and may be increased in accordance with a mare’a oestrus cycle. However, if needed Oestress is suitable for year round use.

Buying in the UK? 

Oestress Powder: 500g RRP £33.50; 1kg RRP 57.50; 2.5kg RRP £135 Purchase here

Oestress Liquid: 1litre RRP £28.99; 2litre RRP £51.99; 5litre RRP £120 Purchase here

Buying the US? 

Oestress Liquid: 1 litre RRP $65.32 Purchase here

Science Supplements HormonAidScience Supplement HormonAid

HormonAid is designed to work alongside the natural cycle of the mare, helping to relieve tension and support a more amenable demeanour. Science Supplements research studies indicate that owners should start to see changes in their mare within three to five days of feeding.

RRP £44.99 (US$56.49) for 1.55kg

Buying in the UK? Purchase here

Buying in the USA? Purchase here 

Dodson & Horrell Stroppy MareDodson & Horrell Stroppy Mare

This product contains a comforting blend for your hormonal mare. It includes chamomile and vervain for their calming properties, St John’s wort and chaste tree berries to support normal hormone function and raspberry leaves and peony petals for nutritional support of the reproductive system.

RRP from £18.78 (US$42.43) for 1kg

Buying in the USA? Purchase here

Buying in the UK? Purchase here

Global Herbs FriskyMare PlusGlobal Herbs FriskyMare Plus

FriskyMare Plus is a traditional herbal formula designed to help with the behaviour and comfort of cycling mares. This calming supplement helps to support hormonal mares and provides quick and effective results. It is particularly useful during the breeding season, when owners worry about oestrus. It is not suitable for pregnant mares or mares trying to conceive.

RRP from £38.10 (US$52) for 1kg

Buying in the UK? Purchase here

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Omega Equine Agnus CastusOmega Equine Agnus Castus

This supplement from Omega Equine supports hormones and regulates mood. Also known as chaste berry, Agnus Castus is an aromatic shrub that has been used to manage hormone balance for centuries.

RRP from £14.99 for 1kg

Buying in the UK? Purchase here

Equine America No More MoodsEquine America No More Moods

This liquid supplement contains chaste tree extract which has been used for centuries to support hormone balance and temperament, especially during the oestrus cycle in a mare but also geldings and non-breeding stallions. No More Moods also contains magnesium and vitamin B1 to support muscle function and the nervous system to further promote comfort and calm behaviour which may be associated with hormonal changes. No More Moods is a palatable liquid that is easily mixed into feed. Being low in sugar means it is suitable for equines who need a low-sugar diet, such as good doers/those who are overweight, and Cushing’s and Equine Metabolic Syndrome sufferers. It is not suitable for pregnant/lactating mares or breeding stallions.

RRP £46.50 (US$80.33) for 1 litre

Buying in the UK? Purchase here

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Premier Performance Sassy Mare PlusPremier Performance Sassy Mare Plus

Sassy Mare Plus is formulated with a specific blend of herbs, minerals, vitamins and amino acids. It contains chaste tree berry (also known as Agnus Castus), raspberry leaf, black cohosh and milk thistle. Premier Performance offers palatability samples for £5 so you can try before you buy a full pack.

RRP from £26.25 or 540g

Buying in the UK? Purchase here

Sassy Mare cookies are also available. RRP from £9.40 for 5 cookies. Purchase here

Equilite Herbs RelaxHer BlendEquilite Herbs RelaxHer Blend

This natural botanic blend helps mares to regulate their hormones while having an calming effect, allowing the mare to better focus on training, manage irritability and depression, reduce restlessness, and handle stress better. This supplement is formulated to aid in relaxation of mares.

RRP from $89.95 for 2lb

Buying in the US? Purchase here

Feedmark HormoneaseFeedmark Hormonease

Hormonease is a herbal supplement that supports a mare’s temperament and hormone balance, helping to stabilise mood swings throughout their oestrus cycle. This product contains a blend of powerful herbs, including Chastetree Berry, which targets the pituitary gland to aid hormone control, maintaining normal levels of oestrogen production. Hormonease™ helps to settle extreme behaviour and is effective for both ‘moody’ mares and ‘riggy’ geldings. Palatability samples are available for £5.

RRP from £59.99 for 1.25kg

Buying in the UK? Purchase here

EquiNutrive Moody MadamEquiNutrive Moody Madam

This supplement is 100% natural and maintains hormone balance to support mares through their season.

RRP from £45.99 for 1kg

Buying in the UK? Purchase here

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