HealthWatch: Lower Airway Inflammation

‘Breathalyzer’ Helps Diagnose Lower Airway Inflammation
Based on diagnostic tests currently used in human medicine, researchers from the University of Glasgow in the United Kingdom say an easy and noninvasive analysis of “exhaled breath condensate” (EBC) could lead to improved diagnosis and monitoring of lower airway disease in horses.

Lower airway inflammation (LAI) in horses can include recurrent airway obstruction and inflammatory airway disease. Signs of lower airway disease include cough, mucopurulent discharge, abnormal tracheal and lung sounds, decreased performance, increased respiratory effort, and/or respiratory distress.

“The current diagnostic test of choice for LAI in horses is analysis of fluid obtained by a bronchoalveolar lavage,” said Dr. Kristopher J. Hughes, a senior lecturer from the Faculty of Veterinary Medicine at the University of Glasgow.

Hughes said that in human medicine, analysis of exhaled breath condensate is a useful technique for the detection of inflammatory diseases of the lower airways, including asthma. The condensate can be assessed for the presence and concentration of various compounds.

To determine if either pH or hydrogen peroxide in the EBC from horses was related to lower airway inflammation, Hughes and colleagues collected EBC from 11 healthy horses and five horses with inflammation.

“In our study, we found a trend for a reduced pH in the airways with airway inflammation, consistent with findings of human studies that have documented airway acidification in patients with lower airway inflammation” said Hughes. “EBC has potential to contribute to a better understanding of (lower airway inflammation) in horses and could prove to be an invaluable diagnostic and monitoring tool.”

Researchers Need Owners’ Help
Horse owners around the world are being asked to participate in an online questionnaire to help researchers better assess the issues of parasite control and dewormer resistance. The study is part of a collaborative effort among equine parasitologists in the United States, Denmark, and Germany.

Horse owners can find a link to the survey in article #14420 on

Topics include parasite control strategies, drug resistance (parasite resistance to dewormers), factors behind parasite control decisions, veterinary involvement, and selective treatment.

Horses, Human Heart Rates
An increase in a human’s heart rate affects the heart rate of the horse he or she is leading or riding, researchers at the Swedish University of Agricultural Sciences recently reported.

Dr. Linda Keeling and colleagues tested horses and riders to see if humans inadvertently communicate fear and anxiety to horses. Using heart rate as a fear indicator, the researchers asked 20 people with varying levels of horse experience to walk and ride 10 horses from Point A to Point B four times. The researchers told participants an umbrella would open as they rode or led the horse on the fourth pass. The umbrella never opened, but heart rates in both horses and humans increased during the fourth trip between the points, when the human expected the umbrella to open.

If you are a nervous person leading or riding a horse, your nervousness might increase the likelihood of the reaction you are anxious to avoid.

Transport, Housing Stress Reflected in Hormone Levels
Transport and housing affect horses’ stress levels, according to Shannon Garey, a PhD candidate who presented results of an ongoing study at the 2009 Equine Science Society meeting, held May 29-31 in Keystone, Colo.

Researchers measured cortisol, a stress hormone, in yearling horses that had never been transported, both before and during a six hour-ride in a semitrailer. The horses rode either in groups or in individual stalls. The results indicated that grouping during transport made no significant difference; all horses were equally stressed by hauling. All levels returned to normal within two hours after the haul. After the transport trial, the researchers moved the horses from group housing to individual stalls. This change caused a nearly threefold increase in cortisol. After 35 days of being stalled, the horses’ cortisol remained above the pre-hauling levels.

Excerpted from The Horse: Your Guide to Equine Health Care. Free weekly newsletters at