How does it work?

It's thought that horses with symptoms over breathe. In humans over breathing has been found to reduce carbon dioxide levels.

Low carbon dioxide levels have a range of detrimental effects on the physiology, such as lack of oxygen as shown in this brain scan, which lead to damage and symptoms.

Equine Breathing works to simply help horses regain normal breathing and physiology

Contents on this page

Breathing too much
Reducing the breathing
Why is carbon dioxide so important?

Adrenaline, compensatory mechanisms and lactic acid
Why does a horse start over breathing?
Why does a horse's breathing deteriorate?

The idea behind Equine Breathing is that it reduces over breathing back towards normal levels which restores carbon dioxide levels and normal physiological functioning and so helps to reverse the damage and symptoms.

This proposal has its origins in scientific studies of human respiration physiology reviewed in the prestigious New England Journal of Medicine (see quote below), although as is often the case equivalent scientific studies on horses have yet to be carried out.

"...extensive data from a spectrum of physiological systems indicate that hypocapnia (low carbon dioxide) has the potential to propagate or initiate pathological processes. As a common aspect of many acute disorders, hypocapnia may have a pathogenic role in the development of systemic diseases."

quote from;

Hypocapnia by John G Laffey MD and Brian P Kavanagh MB
N Engl J Med Vol 347 No. 1 July 4 2002

Woman feeling ill from blowing up balloons ie breathing too much
Equine Breathing

Breathing too much

For optimal functioning the human body needs carbon dioxide in the lungs at nearly 200 times higher levels than the concentration in the outside air. Being a gas, carbon dioxide diffuses from places of high concentration (the body) to low concentration (the air). When you breathe in a lungful of air, carbon dioxide immediately diffuses into it from your body and is then expelled as you breathe out. So the lungs are a constant seat of loss of carbon dioxide. Normally this loss is compensated by the body's production of carbon dioxide.

The body produces carbon dioxide as a result of respiration or metabolism. When muscles are worked aerobically the rate of carbon dioxide production increases.  However, if the in and out breath become larger than normal as in over breathing, more carbon dioxide is lost than is created by cellular respiration and levels in the lungs drop. You can feel the negative effect of breathing too much by for example blowing up balloons or just taking lots of very deep breathes, but as it's not good for you, I don't recommend it.

Breathing is controlled by the respiratory driver in the brain. It is triggered by carbon dioxide. If carbon dioxide levels fall* due to chronic over breathing, the respiratory driver gradually becomes recalibrated to lower levels of carbon dioxide and fails to bring the breathing back to a normal level.

Reducing the breathing

If the in and out breath are reduced back to optimal levels using Equine Breathing, less carbon dioxide is lost and carbon dioxide levels gradually build back up.

So although low levels of carbon dioxide can cause problems, the good news is that the damage is reversible and increasing the level of carbon dioxide results, it's believed, in healing of that damage. Increasing the carbon dioxide level towards normal therefore can help the horse to heal.

Equine Breathing sessions have been found (by use of a capnometer) to increase carbon dioxide levels and regular sessions appear to help reset the brain’s respiratory driver, gradually enabling it to regain normal breathing at reduced, optimal levels.

**Breathing specialist Anders Lönedal finds that in severe cases of over breathing in people the compensatory mechanisms break down and then carbon dioxide levels become much higher than normal. It seems likely that this abnormally high co2 level could happen in horses too. Reducing the breathing to normal remains the solution.

Why is carbon dioxide so important?

The reason low levels of carbon dioxide (and therefore over breathing) can affect such a wide range of ailments and conditions is because it is one of the body's main regulators and has five critical functions.

Oxygen availability

Blood takes up oxygen in the lungs and delivers it to the cells of the muscles and organs. A century ago Christian Bohr discovered that carbon dioxide is needed to make this happen. The lower the carbon dioxide levels the less oxygen is released to the tissues.

The result of this ‘Bohr effect' is that the more air you breathe in, the more oxygen you take in but the more carbon dioxide you lose, so paradoxically the LESS oxygen is available to you. If you try taking rapid deep breaths for just a few minutes or blow up several balloons quickly, you will start to feel dizzy or head achy. This is the lack of oxygen in your brain. This effect is quickly dispelled by taking reduced, gentle breaths.

Cells 'burn' fats and carbohydrates with oxygen to gain energy which enables them to perform their various functions eg detoxification (liver), movement (muscles), thinking (brain). If oxygen is unavailable the cells have to switch to anaerobic respiration which produces only a small fraction of the energy. And instead of producing much needed and useful carbon dioxide and water, anaerobic respiration produces lactic acid, which needs to be removed.

Hypoxia or lack of oxygen is a damaging effect that underlies many ailments. Muscles and organs including the brain work poorly under the stress of not enough oxygen, resulting in fatigue and poor concentration.

Bohr effect; increased Co2 releases more 02 from the blood

Acid/alkaline balance

Carbon dioxide is the main buffer for the body’s fluids, keeping them at the correct pH level. Cells die if the pH changes only a little from the biological norm.

When carbon dioxide is low the body has to use other mechanisms for maintaining viable pH levels. An example is the excretion by the kidneys of substances such as buffer bases which may then fall to low levels.

Countless biochemical reactions go on in the body and require a specific chemical environment. Many of these reactions are disrupted when the acid balance is disturbed causing malfunctioning for example of the immune and endocrine (hormone producing)systems.

Changes is the electrolyte balance disrupts calcium mechanism which may result in muscle spasm and stiffness, arthritis and osteoporosis.

Smooth muscle functioning

Carbon dioxide is essential to allow the relaxation of smooth muscle. Internal organs such as the digestive tract and blood and respiratory vessels are bounded by smooth muscle. Lack of carbon dioxide causes constriction and spasm of vessels resulting in colic, poor circulation and respiratory difficulties to name but a few.

Nervous system cell functioning

At low levels of carbon dioxide nerve cells become hypersensitive so that any stimulus of noise, light, touch (grooming for example) etc can be painful.

Horses exhibiting nervous stress are not necessarily like that because it’s their personality, they may have a biochemical imbalance. This imbalance can be remedied by returning carbon dioxide to optimal levels and the nervous stress disappears.

Biosynthesis of amino acids, lipids and carbohydrates

Carbon dioxide is required for the production of many cellular products essential for healthy functioning and is involved in biochemical reactions involving nearly all vitamins and minerals.

The importance of carbon dioxide in these vital functions means that the effect of low carbon dioxide resulting from poor breathing may be shown in a large range of different illness and conditions.

The good news is that the detrimental effects of low carbon dioxide are reversible.

We think that Equine Breathing works to replenish carbon dioxide levels and as they increase and return to normal levels, these physiological functions that were compromised by the low carbon dioxide, start to work properly once more, and symptoms can diminish and disappear.

Other effects of over breathing


Over breathing causes the body to produce adrenaline which increases the heart rate and takes the body from the relaxed ('anabolic' or 'parasympathetic') state into the flight or fight, or 'catabolic'  state. This is an evolved response so that in time of danger, resources and are channelled into maximum muscle activity. This gives the horse the best chance to save its life by fleeing.

By evolutionary design the catabolic state should be an emergency and therefore short lived state of being. By design the adrenaline rush would be followed by strenuous physical exertion which boosts carbon dioxide levels and help the body back into the relaxed 'anabolic' state once the emergency is over. This burst of activity is usually is not permitted in our horses' lives.

In addition, if a horse is generally stressed and chronically over breathes a vicious cycle sets up because adrenaline also acts to directly increase breathing.

It appears that by reducing breathing and adrenaline production, Equine Breathing puts the horse back into the anabolic state of relaxation, characterised by increased immune cell production, cell repair and replacement - in other words - healing.

horse sleeping in Equine Breather
Equine Breathing

Compensatory mechanisms

Some effects of low carbon dioxide would be fatal if the body did not turn on emergency compensatory measures, such as excretion of buffer bases by the kidneys. Athough life saving, these compensatory measures have their own unwelcome side effects including depletion of the essential buffer base reserves and substances such as magnesium.

Compensatory mechanisms are slow to turn off so if the breathing is reduced, allowing carbon dioxide to build up (a good thing) the ongoing compensatory mechanisms push the body out of equilibrium and it does the quickest thing to regain equilibrium which is to increase the breathing again (a bad thing).

This makes it difficult for a horse (or person) to regain normal breathing without an organised training program. Regular training gradually enables the body to turn off the compensatory mechanisms as they are no longer needed.

Lactic acid

Low carbon dioxide results in lack of oxygen for the cells. Muscle cells go into anaerobic respiration and produce lactic acid instead of carbon dioxide. Lactic acid builds up and is toxic and compromises muscle function, but it also acts directly on the respiratory driver to increase breathing. This further reduces carbon dioxide levels.


For more details of the physiology see this free download, kindly made available with permission from the author;
A brief overview of the Chemistry of Respiration by Peter M. Litchfield, Ph.D. California Biofeedback. Vol 19, No 1 2003

See also the Graduate school of Behavioural Health Sciences website which contains useful information about the physiology of over breathing.

and the Normal Breathing website

Breath - The new science of a lost art by James Nestor.  A must read if you are interested in the latest science and oldest traditions relating to the connection between breathing and health

Why does a horse start over breathing?

The main triggers that can initiate over breathing are

  • emotional stress
  • physiological stress
  • over eating rich food
  • inactivity
  • copying
  • toxic stress
  • over heating

Emotional stress

Horses are flight animals that are evolved to live in the constant social interaction of herd life. Shutting horses in stables on their own denies these basic instincts and can cause emotional stress.

Physiological stress

Despite centuries of domestication horses retain the physiology and anatomy of flight animals. They have evolved to be constantly on the move, covering large distances and eating lightly most of the time. These lifestyle elements are essential for complete health.

However many horses these days are kept inactive and fed high energy low fibre food which is alien to a horse's natural diet and periods of hunger can occur between meals.

Horses may have their temperature regulatory system undermined by the use of artificial clothing and therefore overheat and chill at times.

Illness or injury can trigger over breathing.


Horses it seems, like humans tend to co-ordinate their breathing to the pattern of the worst, breather. A newly weaned youngster that is over breathing is likely to have a bad effect on the breathing of new stable or field mates.

Horses also seem to copy over breathing by humans. So over breathing whilst handling horses is likely to have a detrimental effect on the horses' breathing pattern. These days most people over breathe for many of the same reasons that horses do. The deterioration of human breathing over the last century has been charted in various research papers cited in Artour Rakhimov's book, Normal Breathing .

Toxic stress

Any chemicals that are not useful to the horse's body have to be detoxified and eliminated (or stored). Today's horses have to deal with wormers, veterinary drugs and treatments, fly sprays, food supplements, food additives and traces of pesticides in food or in spray drift.

Why does a horse's breathing deteriorate?

Once a horse has started to over breathe, their breathing tends to continue to deteriorate. There are several suggested causes for this. Over breathing causes an increase in adrenaline production which causes further increases in breathing.

Falling carbon dioxide levels result in production of lactic acid in the tissues which directly acts on the respiratory driver and causes increased breathing.

Falling carbon dioxide levels require the body to initiate various compensatory mechanisms to avoid fatal consequences. These are slow to turn off, so if breathing is reduced, the resulting increased carbon dioxide level, upsets the physiological balance. Whilst the compensatory mechanisms are still in effect, the body attempts to restore the former unhealthy balance by increasing breathing again to blow off the newly gained carbon dioxide eg in snorts or coughs.

These factors work to encourage over breathing, so carbon dioxide levels gradually fall and the respiratory driver in the brain becomes recalibrated to lower levels of carbon dioxide. It then maintains the increased breathing, rather than restoring normal (reduced) breathing.

So once a horse (or human) starts to over breathe it is difficult for them to regain their natural breathing pattern without help. An Equine Breathing program maintains reduced breathing long enough for the body to readjust towards more healthy breathing patterns.

Horses with normal breathing patterns, in the absence of over breathing triggers, retain that breathing pattern through their own natural body control.