Equine Asthma

What is equine asthma?

Equine asthma is a long-term inflammatory condition affecting the horse's lower airways — the tubes that carry air into and through the lungs.

When these airways become inflamed, they can become more sensitive and reactive. The lining may swell, more mucus can be produced and the muscles surrounding the airways can tighten. Together, these changes make it more difficult for air to move freely through the lungs.

Some horses have relatively mild disease and may show little more than an occasional cough or reduced performance. Others develop severe disease in which breathing can become noticeably difficult even while the horse is standing quietly.

Equine asthma is not an infectious disease and cannot be passed from one horse to another.

Other names you may hear

Equine respiratory terminology has changed considerably over the years. Your vet, trainer or another horse owner may use terms such as:

IAD — Inflammatory Airway Disease
An older term generally associated with what is now described as mild-to-moderate equine asthma. The horse's lower airways are inflamed, but the horse will not normally have obvious difficulty breathing while at rest.

RAO — Recurrent Airway Obstruction
An older term generally corresponding to severe equine asthma. In susceptible horses, exposure to environmental triggers causes considerable airway inflammation, mucus production and narrowing of the airways.

COPD — Chronic Obstructive Pulmonary Disease
A term historically used for horses with chronic respiratory problems. Although owners and practitioners may still use "COPD", equine asthma is now the preferred terminology.

Heaves
An older, commonly used name for severe equine asthma. It describes the increased muscular effort some affected horses make when breathing out.

Broken wind
A much older expression sometimes still heard when discussing horses with longstanding severe respiratory disease.

Summer pasture-associated equine asthma
Sometimes abbreviated to SPASEA or historically referred to as SPRAO. These horses may become worse at pasture, particularly during certain seasons, rather than being predominantly affected by the stable environment.

All these terms describe, or have historically described, conditions involving inflammation and obstruction of the horse's lower airways.

What is actually happening inside the horse?

Think of the horse's airways as a branching system of tubes carrying air deep into the lungs.

In a healthy horse these tubes allow air to pass relatively freely.

With equine asthma several things can happen at the same time:

• the airway lining becomes inflamed and swollen
• excess mucus may accumulate
• the muscles surrounding the airways can tighten
• the airways become unusually sensitive to inhaled particles
• chronic severe inflammation can gradually alter and thicken the airway walls

The result is a narrower passage through which the horse must move air.

This is particularly important during exercise, when a horse needs to move very large volumes of air through its respiratory system.

In severe cases the horse may have to make considerably more muscular effort simply to breathe normally at rest.

Mild-to-moderate equine asthma

Mild-to-moderate equine asthma can be surprisingly difficult for owners to recognise.

The horse may appear perfectly comfortable in the stable or field but develop problems when exercising.

Signs can include:

• an occasional cough
• coughing when exercise begins
• reduced stamina
• taking longer to recover after exercise
• apparently tiring earlier than expected
• reluctance or inability to maintain previous levels of work
• nasal discharge in some horses
• unexplained reduction in performance

Sometimes the first indication is simply:

"He doesn't seem to be performing like he used to."

That is important because respiratory disease does not always produce dramatic breathing symptoms.

Severe equine asthma

With severe asthma the changes within the airways can substantially restrict airflow.

Signs may include:

• frequent or persistent coughing
• increased breathing effort
• nostril flaring
• wheezing or other respiratory noises
• nasal discharge
• reduced exercise tolerance
• obvious abdominal effort when breathing
• difficulty breathing even when resting

A horse with longstanding severe asthma may develop what is sometimes called a "heave line".

This is a visible line along the lower abdomen caused by enlargement of the muscles that have repeatedly been used to help force air out of obstructed lungs.

Difficulty breathing at rest requires veterinary attention

A horse that is visibly struggling to breathe while standing quietly should not simply be regarded as having "a bit of a cough".

Significant respiratory difficulty can be serious and requires veterinary assessment.

What can trigger equine asthma?

Many affected horses are particularly sensitive to tiny airborne particles known as aeroallergens.

These can include:

• dust from hay and forage
• mould spores
• fungal material
• bacteria and bacterial components within organic dust
• dust from bedding
• plant particles
• pollen
• mites
• ammonia and other irritating gases
• dust generated during mucking out or sweeping
• airborne particles from arenas and other working surfaces

These particles can be extremely small.

A stable or bale of hay therefore does not have to look dusty to contain particles capable of reaching deep into the horse's lungs.

The stable environment matters

For many horses with asthma, reducing exposure to airborne irritants is one of the most important parts of long-term management.

Consider the horse's whole breathing environment, not simply its bedding.

This can include:

Forage
Dry forage can be a major source of respirable dust. Depending upon the individual horse and veterinary advice, appropriate alternatives or preparation methods may help reduce exposure.

Bedding
Choose clean, low-dust bedding appropriate for the horse.

Ventilation
Fresh air needs to move through the stable continuously. A stable feeling warm and cosy to a person does not necessarily mean it provides a good respiratory environment for a horse.

Mucking out and sweeping
Both can put enormous quantities of particles into the air. Ideally, susceptible horses should be elsewhere while dusty yard work is carried out and while the dust settles.

Forage and bedding storage
Storing hay or straw immediately above or alongside horses can contribute to airborne dust.

Feeding position
Where practical and hygienic, feeding forage from a low position can encourage a more natural head position and assist normal airway drainage.

Turnout
More time outdoors can dramatically reduce exposure for some horses — although horses with pasture or pollen-associated asthma may require a different approach.

There is therefore no single management system that is correct for every asthmatic horse.

Why one horse can be affected when another isn't

Two horses can live on the same yard, eat the same forage and sleep on the same bedding while only one develops obvious asthma.

The affected horse's airways are unusually responsive to environmental challenges.

This is why equine asthma should not automatically be interpreted as evidence that a stable or yard is badly managed.

However, once a susceptible horse has been identified, reducing its exposure to respiratory irritants becomes extremely important.

How is equine asthma diagnosed?

Your vet will consider the horse's history, symptoms, environment and level of work before deciding which investigations are appropriate.

You may hear some of the following terms.

Auscultation

This simply means listening to the horse's chest with a stethoscope.

The vet is listening for the movement of air and sounds such as wheezes or crackles that may indicate narrowing of the airways or mucus.

Endoscopy

A flexible camera is passed through the nose so the vet can examine parts of the respiratory tract.

This can reveal inflammation and accumulations of mucus.

BAL — bronchoalveolar lavage

Owners sometimes hear this described as a lung wash.

A small amount of sterile fluid is introduced into part of the lower airway and collected again.

The cells contained within that fluid can then be examined. Different types and proportions of inflammatory cells can provide important information about what is happening inside the lungs.

BAL is particularly useful because a horse can have significant lower-airway inflammation without showing dramatic outward symptoms.

Your vet may use additional investigations where necessary to rule out infection or other respiratory disease.

Treatment

Treatment depends upon the severity of the disease and the individual horse.

Veterinary treatment may include:

Corticosteroids
These reduce inflammation within the airways.

Bronchodilators
These relax muscles surrounding the airways, helping them open and allowing air to move more easily.

Inhaled medication
Some medications can be administered through equine inhalation devices, delivering treatment directly into the respiratory system.

Medication can be extremely important, particularly during an acute episode.

However, medication and environmental management perform different jobs.

A bronchodilator may open constricted airways and corticosteroids can suppress inflammation, but continuing to expose a susceptible horse to high concentrations of the particles triggering that inflammation can allow the problem to return.

For this reason, environmental management is a fundamental part of controlling equine asthma rather than an optional addition to medication.

Can equine asthma be cured?

The answer depends partly upon the type and severity of disease.

Some horses with mild-to-moderate asthma can improve considerably when the underlying inflammation and environmental triggers are addressed.

Severe equine asthma is more commonly regarded as a long-term condition requiring ongoing management.

Many affected horses can nevertheless have a good quality of life when their environment, workload and veterinary treatment are appropriately managed.

Longstanding severe inflammation can cause structural changes within the airway walls — sometimes called airway remodelling — and some of these changes may not be completely reversible.

Early recognition and effective management therefore matter.

Exercise and the asthmatic horse

Do not assume that coughing during exercise is simply the horse "clearing its throat".

Exercise enormously increases the amount of air moving through a horse's respiratory system.

Mild airway inflammation that is barely noticeable at rest can therefore become much more significant during work.

If a horse repeatedly:

• coughs when exercise begins
• loses performance
• tires unexpectedly
• struggles to recover normally
• develops unusual respiratory noise
• appears unable to perform work that was previously comfortable

it is sensible to investigate why rather than simply attempting to improve fitness.

Exercise programmes should be discussed with your vet where asthma is suspected, newly diagnosed or poorly controlled.

Supporting respiratory health through nutrition

Nutrition cannot remove an environmental trigger or replace veterinary treatment for equine asthma.

However, an appropriately balanced diet can form part of the wider management of respiratory health.

When choosing feeds or supplements for a horse with respiratory sensitivity, it is also worth considering how the product is presented. Very dusty feeds or powders may be undesirable around a horse whose airways are already sensitive.

Freestep respiratory support

Where a Freestep product specifically formulated to support respiratory health is appropriate, it can be introduced here as part of the horse's wider management programme.

The product presentation should clearly explain:

• what nutritional respiratory support it provides
• its relevant active ingredients
• why those ingredients have been included
• recommended feeding information
• that nutritional support complements rather than replaces environmental management or veterinary treatment

[Insert relevant Freestep respiratory product card and link here.]

When should I contact my vet?

Speak to your vet if your horse develops persistent or recurring:

• coughing
• nasal discharge
• respiratory noise
• reduced exercise tolerance
• unexplained loss of performance
• increased breathing effort
• unusually prolonged recovery following exercise

Seek prompt veterinary advice if your horse shows obvious difficulty breathing while at rest, particularly where there is pronounced nostril flaring, abdominal effort or distress.

The important thing to remember

Equine asthma isn't simply "a cough".

It is inflammation within the horse's lower airways.

A horse with mild asthma may show very few outward signs, while severe asthma can make the physical act of breathing difficult.

The good news is that understanding the horse's environment can make an enormous difference.

Reduce what the horse breathes in.
Control the airway inflammation.
Work with your vet.
Manage the individual horse, not simply the diagnosis.

Suggested graphics

Graphic 1 — Hero graphic

"Equine Asthma — What Happens Inside the Airways?"

Visual:
A clean illustration of a horse with the respiratory tract highlighted, accompanied by two enlarged airway cross-sections:

HEALTHY AIRWAY

• open airway
• thin airway lining
• minimal mucus
• air moving freely

ASTHMATIC AIRWAY

• inflamed/swollen lining
• increased mucus
• tightened airway
• reduced space for airflow

Main caption:
Equine asthma causes inflammation, mucus production and narrowing of the lower airways, making it harder for air to move freely.

Footer:

JCG Health Hub | Equine Asthma
jcgsupplements.com

The JCG identity and website must remain part of the graphic so that if it is printed, downloaded, screenshot or shared independently, its source remains clear.

Graphic 2 — "The Names Have Changed"

A simple owner-friendly terminology graphic.

EQUINE ASTHMA

Mild-to-moderate equine asthma
Previously commonly called:

• IAD
• Inflammatory Airway Disease

Severe equine asthma
Previously commonly called:

• RAO
• Recurrent Airway Obstruction
• COPD
• Heaves
• Broken wind

Summer/pasture-associated severe equine asthma

• May be triggered predominantly outdoors or seasonally.

Bottom message:

Different names — related inflammatory diseases of the horse's lower airways.

Footer:

JCG Health Hub | Understanding Equine Asthma
jcgsupplements.com

This graphic should also be completely understandable when viewed away from the webpage.

Graphic 3 — "Think About What Your Horse Breathes"

A horse centrally positioned with environmental sources arranged around it:

FORAGE
Dust • mould • spores

BEDDING
Dust • organic particles

STABLE
Ventilation • ammonia • stored forage

YARD WORK
Sweeping • mucking out • airborne dust

EXERCISE
Arena dust • airborne particles

OUTDOORS
Pollen • seasonal triggers

Central message:

Managing equine asthma starts with the horse's breathing environment.

Supporting line:

Medication can control inflammation and open the airways. Reducing exposure to respiratory triggers helps address what is provoking them.

Footer:

JCG Health Hub | Equine Asthma
jcgsupplements.com

Again, the JCG Health Hub identity and website should be permanently incorporated into the artwork rather than relying on the webpage surrounding it.