The effect of stable bedding materials on dust levels, microbial air contamination and equine respiratory health

The choice of bedding material affects the quality of air in a stable and, consequently, the respiratory health of horses and humans. The risk of respiratory problems can be mitigated by improving the quality of air in the stable. The choice of bedding material is particularly important in cold climate conditions where horses are kept indoors throughout the year. This study examined the impact of three bedding materials: straw (S), peat with shavings (PS), and crushed wood pellets (CWP). The investigated factors were air contamination, including dust contamination and microbial (bacterial and fungal) contamination, and the condition of the equine respiratory tract. The condition of the respiratory tract was evaluated based on the results of arterial blood biochemistry tests and endoscopic evaluations of the upper respiratory tract. Mechanical dust contamination was lowest for PS (1.09 mg/m3) and highest for CWP (4.07 mg/m3). Bacterial contamination (in CFU - colony forming units) was highest for PS (5.14 log10 CFU/m3) and lowest for CWP (4.81 log10 CFU/m3). Fungal air contamination was lowest for CWP (4.54 log10 CFU/m3) and highest for S (4.82 log10 CFU/m3) and PS (4.88 log10 CFU/m3). An analysis of physiological indicators revealed that all horses were clinically healthy regardless of the type of applied bedding. The type of bedding material did not exert a clear influence on arterial blood biochemistry or the results of endoscopic evaluations of the respiratory tract; however, the use of alternative for straw bedding materials improved endoscopy results.