Bedding, Diet Impact Equine Asthma: What Can You Do?

Horses maintained primarily outdoors generally have healthier airways and a lower incidence of asthma than those kept predominantly in stables. For a variety of reasons, such as limited acreage, inclement weather, and fear of injury, stabling remains a necessity. When faced with stabling, what bedding best minimizes damage to respiratory tissues?

Common beddings include straw, shavings, sawdust, straw pellets, peat moss, and recycled paper. Each has advantages and drawbacks. Take straw, for example. Straw, an economical bedding choice, provides insulation and cushion, thereby promoting normal sleeping behaviors. Straw does not, however, absorb urine and ammonia well, and produces high levels of dust and other aerosolized particles.

Although bedding has been the topic of many studies, a definitive answer regarding optimal bedding remains elusive. In one of the most recent attempts to find answers, a group of Polish researchers* assessed the impact of straw, dedusted peat with shavings, and crushed wood pellets on air contamination.

During the study, eight horses were maintained on each type of bedding for three weeks. At the beginning and end of each phase of the study, red and white blood cell parameters, respiratory rate, and lung sounds were assessed in addition to arterial blood gas evaluations and endoscopic examinations.

“All horses remained healthy during the study, and none of the beddings significantly altered any of the blood values measured,” said Kathleen Crandell, Ph.D., an equine nutritionist for Kentucky Equine Research (KER).

Nonetheless, several important differences between the different types of bedding were noted:

• Crushed wood pellets produced fewer aerosolized fungal spores and bacteria but the most dust;
• Bacterial contamination of the stable air was similar for straw and peat with shavings;
• Straw and peat with shavings produced similar fungal air contamination; and
• Endoscopic exams were the least favorable on straw.

“The study period was short, which could minimize the impact of any bedding on airway health, but this study did confirm that straw was overall the least desirable bedding material of the three,” Crandell summarized.

In addition to bedding type, barn ventilation and feed choices also have a huge impact on the health of airways. For example, should you offer hay, and if so, should it be manipulated in any way to reduce dust?

“Low-dust hay or even hay alternatives could help horses with equine asthma. Consult a KER nutrition advisor today to help find healthier feed options, even for horses housed primarily outdoors,” recommended Crandell.

*Kwiatkowska-Stenzel, A., D. Witkowska, J. Sowińska, et al. 2017. The effect of stable bedding materials on dust levels, microbial air contamination and equine respiratory health. Research in Veterinary Science. 115:523-529.