Horse Respiratory Health: Dust Management

Airborne dust in stables is the primary driver of equine asthma. Systematic dust reduction through management changes dramatically improves respiratory welfare in stabled horses.

Key Facts

Respirable dust in stables comes primarily from hay, bedding, and the combined effect of multiple horses in enclosed spaces
A stable horse inhales approximately 60,000 litres of air daily, making air quality critically important
Organic dust containing fungal spores triggers the allergic airway inflammation of equine asthma
Soaking hay for 30-60 minutes reduces respirable particle count by approximately 90%
Haylage reduces dust exposure compared to hay but carries risks of Listeria contamination if poorly fermented
Total dust load matters — multiple marginally dusty components combine to cause clinically significant exposure

Welfare Considerations

Respiratory disease in horses exists on a spectrum from subclinical airway inflammation to severe asthma — but all points on this spectrum involve the horse breathing air containing particles that trigger inflammation. Even horses that do not show obvious respiratory signs may be experiencing subclinical inflammation that reduces performance and welfare. Reducing stable dust through management changes improves the respiratory health of all stabled horses, not just those with diagnosed asthma.

What You Can Do

Soak hay for 30-60 minutes before feeding in stable environments
Use dust-extracted or dust-free bedding (shavings or rubber matting) rather than straw
Ensure stables have adequate cross-ventilation with ridge ventilation and open top doors
Do not store hay in lofts directly above stabled horses — dust falls through into breathing zones
Maximize turnout on pasture where respiratory allergen exposure is minimal
Have your vet perform endoscopic airway assessment for any horse with performance decline or cough