Researchers at the University of Adelaide are investigating the frequency of equine asthma and risk factors for its presence in horses across Australia, and whether the recent bushfires have increased respiratory distress.
"We know from studies of race horses overseas that up to 57-80% of horses have a mild to moderate form of asthma and that as many as 14-20% of horses may have a severe form of asthma but we don't currently have much information about prevalence in Australia," says Dr. Surita du Preez, specialist veterinarian in equine internal medicine at the University's Equine Health and Performance Centre at its Roseworthy campus.
"If we can determine the prevalence of asthma in our horses here, and identify Australian-specific risk factors for development of equine asthma, we may be able to prevent disease development, and better manage horses that are already affected."
Asthma is one of the main causes of poor performance in horses, making them unwilling to go forward in race, sport or pleasure riding situations.
Dr. du Preez and honours student Jewel Azaria Tan are conducting a survey of horse owners with questions about their horses' health, use, and management including feeding and housing practices. Owners will also be asked if they have noticed increased respiratory distress in their horses after the bushfires.
"The mild to moderate form of asthma can affect horses of all ages and disciplines, not just racehorses," says Dr. du Preez. "It can result in intermittent coughing or nasal discharge or both.
"Horses have a poorly developed cough reflex and should not cough at all. If they cough it usually signifies a problem, unlike in people who have a very well-developed cough reflex and may cough because of a simple throat tickle.
"The severe form of asthma affects middle aged to older horses and is a life-long, progressive disease which if left unmanaged can results in severe airway remodelling and obstruction to airflow, resulting in breathing difficulties."
It is unclear if equine asthma has become more common, or if horses with the disease have been more severely affected, since the bushfires.
Dr du Preez says: "We hope through this survey to establish some baseline information about the numbers of horses affected by bushfires and whether the owners noticed an increase in respiratory signs."