Equine Asthma in Horses: Symptoms, Causes & Prevention (Plus Feeding Tips to Reduce Dust)

Equine Asthma: Understanding, Recognising, and Preventing Respiratory Issues

Equine asthma is one of the most common causes of chronic coughing and reduced performance in horses. It can range from mild, intermittent signs through to more severe breathing difficulty that impacts day-to-day comfort and quality of life. The good news is that management changes—especially around dust control—can make a huge difference.

This article covers what equine asthma is, how to recognise it, and practical prevention steps, including a simple feeding change that can help reduce dust exposure: feeding hay off the ground rather than in hay nets (with an important note about sand intake).

What is Equine Asthma?

Equine asthma is a chronic inflammatory condition of the lower airways (bronchi and bronchioles). When a sensitive horse inhales irritants—like dust, mould spores, pollen, or stable ammonia—the airways can become inflamed and narrowed. This makes breathing harder and can trigger coughing and exercise intolerance.

The two common forms

1) Recurrent Airway Obstruction (RAO)
Often seen in mature horses (commonly over six years). It’s frequently triggered by dust and mould from hay, bedding, and stable environments. Signs can worsen in stabled horses or during dry, dusty conditions.

2) Inflammatory Airway Disease (IAD)
More common in younger horses, and sometimes linked to infections or ongoing irritant exposure. Signs can be milder but still affect performance and comfort.

Clinical Signs to Watch For

Early recognition matters—many horses show subtle changes before it becomes more obvious. Common signs include:

• Coughing (especially during/after exercise; often dry and persistent)

• Increased respiratory rate at rest

• Nasal discharge (often clear or white)

• Laboured breathing (flared nostrils, abdominal effort, “heave line” in more advanced cases)

• Exercise intolerance (fatigues quickly, poor recovery)

• Reduced appetite and weight loss (in longer-term cases)

• Increased effort even at rest in severe cases

If your horse has ongoing cough, breathing effort, or performance drop, it’s worth involving your vet—especially to rule out infections or other causes.

Preventing Equine Asthma: Practical Management That Works

For most horses, the biggest improvements come from reducing what they inhale day after day. Think “air quality first.”

1) Improve ventilation and reduce dust

• Maximise airflow in stables and yards

• Use low-dust bedding

• Avoid sweeping or using blowers when horses are inside

• Store hay and bedding away from stabled horses where possible

2) Choose the cleanest forage you can

• Feed high-quality hay with low dust and mould

• Consider soaking or steaming hay to reduce airborne particles (your vet can advise what suits your horse and conditions)

3) Increase turnout time

Fresh air helps. More turnout and less time in enclosed, dusty environments is often one of the most effective changes for respiratory horses.

4) A simple but powerful change: feed hay off the ground (not hay nets)

One way to help reduce respiratory irritation is to feed hay at ground level rather than from hay nets. Why?

• More natural head position: When the horse’s head is down, airway drainage and clearance tends to be better than when eating with the head raised.

• Less dust inhaled close to the nostrils: Hay nets can shake and release fine particles right where the horse is breathing.

Important sand-safety note:
Feeding on bare sand can increase the risk of accidental sand ingestion. The solution is simple:
✅ Feed hay off the ground on a matted area, rubber mat, or in a low, wide feeder placed on mats to minimise sand intake.

This gives you the respiratory benefit of ground feeding without the downsides of sandy paddocks.

5) Keep the environment clean

• Regularly clean feed areas, water troughs/buckets, and stable surfaces

• Reduce mould build-up in feed rooms and bedding storage

6) Smart exercise and training

• Warm up gradually and avoid overexertion in dusty conditions

• Monitor recovery and adjust workload when signs flare

• If your horse is symptomatic, speak with your vet before pushing intensity

7) Avoid smoke and air pollutants

Keep horses away from cigarette smoke, diesel fumes, burning-off smoke, and dusty works—these can all exacerbate airway inflammation.

Anti-Inflammatory Nutrition Support: Helpful Add-Ons

While environmental management is the cornerstone, nutrition can support respiratory comfort—especially for horses prone to inflammatory flare-ups.

Omega-3 fatty acids (anti-inflammatory support)

Omega-3s are widely used to support a healthy inflammatory response.

• Linseed (Flaxseed): Rich in ALA (alpha-linolenic acid). Can be fed as freshly ground seed, meal, or oil (as appropriate).

• Chia Seeds: Another ALA-rich omega-3 source that many owners use for general inflammatory support.

• Fish Oil: Provides EPA and DHA, which are considered particularly active omega-3 forms. Some horses accept it well; others need a slow introduction.

Vitamin E (antioxidant support)

Vitamin E can help support antioxidant status, particularly in horses with higher oxidative stress or limited pasture access.

A quick reminder: introduce changes gradually, and work with your vet or equine nutritionist—especially if your horse is on other supplements or has metabolic concerns.

Putting It All Together: Your Asthma-Friendly Checklist 

• Improve stable airflow and reduce dust

• Choose cleaner forage; consider soaking/steaming if needed

• Maximise turnout and fresh air

• Feed hay off the ground to support airway clearance

• Use rubber matting to avoid sand ingestion

• Add omega-3 support (linseed/chia/fish oil) where suitable

• Avoid smoke, blowers, and dusty chores around horses

Need Help Choosing the Right Support?

Oakford Stockfeeds offers a range of feeds and supplements that can support horses prone to inflammation—including linseed-based options, omega-3 supports, and Vitamin E products. Visit us in-store or online and we’ll help you choose what best suits your horse’s workload, environment, and needs.