April 2008 • VOLUME 32 • © HORSES For LIFE™ Magazine

Air Quality in Stables at an American Thoroughbred Racetrack
A research study by Melissa L. May, MSc; Frederik J. Derksen, DVM, PhD; Brett Berthold, DVM; Susan J. Holcombe, VMD, PhD; and N. Edward Robinson, BVetMed, PhD, MRCVS, decided to check the actual air quality in stables at an American racetrack. Concerns were raised when the racehorses had reduced racing performances, thought due in part to accumulation of mucoid secretions in the horses' airways. Those horses not testing positive for bacteria encouraged reseachers to look elsewhere, noting that it has been observed in humans that small increases in ambient fine particles are associated with an increase in patients with upper respiratory infections.

There are of course many sources of particulate matter in any horse environment -- sources such as feed, bedding, and flooring. In the racehorse environment and in some stables, we also need to consider vehicle exhaust, road dust and emissions from any nearby operations.

This study focused on the two different sizes of particulate matter. One a larger size that normally would be deposited in the trachea and then those that were smaller that would penetrate deep within the airways.