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Why does my mare.... get moody

11/07/2012 by We get the opinion of four different experts

Breeding season sees alot of moody mares around. Lets find out what our 4 experts have to say about it.

Craig Simon, BVSc(hons), GPCert(EqP), MACVc(EqSurg), CMAVA - All Horses Vet Services

When a client complains their mare is ‘moody’, they are often referring to unwanted behaviours that may be associated with the oestrous cycle. This is very common and can lead to less than desirable performance.

The ovarian hormones can have a significant impact on the mare’s mood, level of arousal, sensitivity to pain and cognition. The two main hormones involved are oestrogen and progesterone. The levels of each vary, as the mare goes through her normal oestrous cycle. As the mare comes into season the progesterone levels are suppressed and the oestrogen levels rise and the opposite is true when she is not is season. This cycle lasts approximately 21 days, and the mare is in oestrous (season) on average for 5 days.

Every horse is different and the level of behavioural changes will vary between individuals. Most frequently there is a definite change in attitude. Owners may notice behaviours such as tail swishing, difficulties in training, squealing, kicking, hyperexcitability and an increased sensitivity to pain.

It should be remembered that changes in behaviour or mood are not however always linked to the oestrous cycle. It is therefore important to identify when the behaviours are occurring, and under what circumstances. This helps in assessing whether there are indeed behavioural issues linked to the oestrous cycle, or whether other factors such as a source of pain, lameness, equipment or rider issues are involved.

Andrew McLean, PhD - Director, Australian Equine Behaviour Centre

In the absence of health issues which should be investigated by your veterinarian, moody behaviour and irregular cycling can be linked to pain and / or stress in mares who exhibit conflict behaviours (commonly known as resistances and evasions).

Conflict behaviours are a set of responses usually characterized by hyper-reactivity and which arise largely through confusion with training.

In nature horses have control to be free of conflict as they can learn to respond to the environmental pressures, there is predictability in their environment and pain is generally escapable. In contrast, when a horse is trained it is inevitably subjected to many pressures (rein, ‘heavy contact’ leg/spur) and in many cases it is unable to avoid some or all of them.

Recent research has shown a correlation between pain / stress and rising levels of prolactin (the hormone that stimulates milk production after birth and inhibits other hormones responsible for ovulation) which could explain why training related stress and pain would cause hormonal imbalances.

At the AEBC we have observed many times the correlation between irregular cycling of mares and conflict behaviours, and these were successfully resolved when relaxation improved in training. Relaxation ensures the absence of conflict, and is evident when after re-training, the horse correctly and consistently responds to light pressures. We achieve that by re -installing the basic responses to rein and leg pressures – stop and step back from both reins, direct and indirect turns, and the basic leg responses – go from both legs and yield. Once horses are clear and respond consistently to light versions of the pressures, you will notice increased relaxation and a more consistent behaviour.

by Lucy Prior, Gotcha Equine 

As with anything now different with your horse always eliminate the possibility of an issue causing pain or discomfort first. One of the most common causes for mares being moody is changes to their hormone balance. As with all animals including us, different stages of the breeding cycle will have an affect on hormone levels. In some cases where these levels can be out of balance to the point of quite dramatic mood swings. Before you start trying to use hormone correction agents/products I would suggest you look at what could be causing or adding to this imbalance.

Legumes such as lucerne and clover (grass or hay) contain phytoestrogens. The name comes from the Greek phyto = plant and estrogen, the hormone which gives fertility to the female mammals. Recent research has found that legumes containing high levels of phytoestrogens affect fertility levels and can be a contributor to some birthing problems. Breeding studs find after the clover has finished it’s easier to get mares in foal. Field studies found that by deleting phytoestrogens can improve mares’ moody behaviour quite considerably and their cycles can become less obvious. Some geldings have been found to display stallion like behaviour when fed high phytoestrogen diets.

University studies have also found that some tropical grasses contain high levels of phytoestrogens and may be influenced by location and season, e.g. Kikuyu, Pangola, Southern crabgrass and star grass. I would suggest that if you have eliminated all other possible causes you then look at the grasses.

If your mare seems to be affect by dietary phytoestogens it would be wise to also avoid soy products. Devils Claw has been found to be an effective anti-inflammatory and pain killer in horses but it can also have an adverse effect on mares and create very extreme cycles and I would avoid using with ‘moody mares’.

Mares and stallions have higher requirements of calcium than geldings, a large number of tropical grasses and kikuyu bind up calcium and magnesium. Both these elements have been found to help keep horses calm so this is something else to also consider.

Sue Martin – Equine Naturopath, Natural Equine Health.

Unfortunately there may be various reasons for moodiness in mares and therefore it is important to ensure that a full assessment is completed to ensure that everything is covered from discomfort (muscular, teeth, feet and gastric), feeding, supplementation, hormonal imbalance and the reasons why any of these have occurred in the first place.

Checking of tack, training technique and musculature will rule out discomfort in this area as well as an examination of feet and teeth to ensure that the mare is sound in these areas also.

Diet along with the species of grasses and legumes must also be assessed as some clover species contain a high content of oestrogen which may be causing problems to the mare. If the mare is fed a range of supplements and these are causing an imbalance, this could also result in moody behaviour amongst other issues and therefore diet and supplementation must always be considered. An excess of digestible energy (overfeeding) can cause fizzy behaviour and/or gastric issues.

Herbs such as Chaste tree berries to balance hormones, Chamomile flowers to relax the digestive tract and to ease nervousness and analgesics and anti inflammatories such as Devils Claw Root and White Willow Bark are only a few examples of useful herbs. Due to the long list of herbs suited for individuals with specific problems, it’s essential to be guided by a qualified Equine Naturopath.

The points to take into consideration when dealing with a moody mare are –

  • Be sure not to rule out anything.
  • Try not to base the moody behaviour on a hormonal imbalance only.
  • Where has the problem started....pain, diet, training, hormones etc....seek professional advice to ensure you receive the answers to treat the cause rather than just the symptoms. This way your mare will be healthier and feel happier.