Someday people may use a digital audio recorder to evaluate equine respiratory diseases, as well as the air quality of the stable environment.

Marco Duz, MedVet, MRCVS, and his colleagues recorded horses' coughs over 24 hours, then analyzed the coughs by reviewing the digital recording on a computer, which took about 2-3 minutes for every hour of recording time.

"We attached the digital audio recorder to the head collar with the microphone pointing toward the mouth," said Duz of the Weipers Center for Equine Welfare at the University of Glasgow in Scotland.

Cough is a good indicator that something is wrong with the horse. "Studies have shown that the more frequently horses cough, the more severe disease of the lower airways is," said Duz. "Therefore, monitoring cough frequency can provide valuable information about the severity of disease