Airway disease in racehorses more common than thought
Developing an improved understanding of IAD could lead to better health in horses and a more competitive horse racing industry.
A study by Canadian researchers has found that inflammatory airway disease (IAD) in racehorses is more common than previously thought.
In the study, researchers examined lung tissue from 95 deceased racehorses that had actively raced or trained before their deaths. They found that most of the horses had some degree of IAD, with mild to severe airway changes.
The discovery came as a surprise to the team, since previous studies had suggested the disease only occurred in up to half of equine athletes.
“The disease was known to be common in racehorses, but not as widespread as this study reveals,” said study author Professor Jeff Caswell. “The findings suggest that IAD does not result from unique exposure of an affected horse to the stimulus that causes the disease. But rather the research suggests that all racehorses may be exposed, with inflammation of the airways experienced by many”.
Published in the American Journal of Veterinary Research, the study was the first of its kind to assess information on a tissue level. It was also the first to discover airway inflammation in horses not specifically chosen for poor performance.
“None of the deceased horses showed obvious signs of airway inflammation in their final three races,” said co-author Professor Luis Arroyo. “The research shows that inflammation is always prevalent in racehorses, even those that may or may not have respiratory signs.”
The researchers hope that developing an improved understanding of IAD could lead to better health in horses and a more competitive horse racing industry.
The study - Histologic investigation of airway inflammation in postmortem lung samples from racehorses - was conducted by researchers at the Ontario Veterinary College, University of Guelph.
Veterinary practices are being urged to help owners safely dispose of any unused and expired pet medicines - not just antibiotics - during November's Animal Medicines Amnesty. 
