Study suggests steamed hay feed can reduce risk of IAD in horses

Scientists at the Equine Sports Medicine Practice in Waterloo, Belgium have carried out a comprehensive study, “Fungi in respiratory samples of horses with inflammatory airway disease”, which suggests that horses that breathe in aerosolised fungal particles are much more likely to develop inflammatory airway disease than those who don’t, and that the chances of developing the disease can be reduced by 65% by feeding them steamed hay.
731 active sport, race and leisure horses were involved in the study in which clinical data, environmental conditions, and results of a tracheal wash and bronchoalveolar lavage were assessed. Data regarding the type of bedding and hay forage were collected and analysed, and the scientists found the type of bedding and forage provided can be pivotal in the risks associated with IAD and fungal contamination. The authors said: “The alternatives to dry hay other than steaming, such as wetting or soaking the hay, feeding haylage, or commercial, ’dust-free’ hay, all increased the risks of having a positive IAD diagnosis. Soaking the hay did not influence the finding of fungal elements in the TW. However, steaming hay decreased by two-fold the risks of having fungal elements in the TW. The role of fungi in equine IAD needs to be further investigated. Although fungi might not necessarily be the primary cause of IAD, it is possible that deficits in immunity might modify the equine ability to react to infection.”