You only need to be mucking out and turning over a stable bed, with the sun streaming in through the door, to see the amazing amount of miniscule particles filling the air.
The perceived wisdom is that paper and shavings beds are better for horses with allergic airway disease, but there has been little objective assessment on the subject.
They tested wheat straw, softwood shavings, hemp/flax fibre, straw pellets and shredded paper.
The results surprised them; the hemp/flax bed, which was specifically marketed for horses with irritable airways, produced the most particles. Next was the wood shavings sample.
Paper and pelleted straw produced the least particles and wheat straw was somewhere in between.
Straw pellets performed the best and straw was the worst, even though in the lab, shavings had performed worse than the straw.
The vets believed that the difference in air quality between straw and shavings was a reflection of the fact that the straw bed was mucked out and replenished every day, while the shavings were just skipped out.
Further complications were discovered because the straw yielded more moulds than other beds.
“From the respiratory point of view, the best bedding is no bedding,” says Colin Roberts, an ILPH-funded equine internal medicine specialist at Cambridge University Veterinary School.
“You can achieve that in a stable by using rubber matting on its own, but you must get the drainage right. In my experience, horses are fine on it – there are no problems with pressure sores and they lie down happily on it.
“If you have to use bedding, literature suggests that the best types are paper and cardboard, but they must be well managed. Any form of deep litter is out.
“Even healthy horses are better off on dust-free management. What you’re really trying to avoidis mould spores, which are the allergens that cause the most problems. The latest research shows that recurrent airway obstruction [RAO], which used to be called COPD and is similar to occupational asthma in people, may develop if there is any length of exposure to mould.”