Louisiana State University researchers in the School of Veterinary Medicine have begun a study to investigate the effect of viral infections on the immune response of neonatal foals, specifically if exposure to influenza virus reduces the risk for developing recurring airway obstruction (RAO) later in life.

“This study is an evolution of many things we’ve been investigating to understand equine airway disease. It’s become pretty obvious that RAO disorders are a result of allergic reactions,” said David Horohov, MS, PhD, principal investigator and professor of veterinary immunology. “With this study, we’re hoping to provide insight into the consequence of early viral exposure and the tendency of horses to develop allergic immune response in their lungs,” said Horohov.

Fifteen to 20 percent of horses worldwide suffer from RAO, a condition similar to human asthma, representing a significant impact on the equine population and industry. While RAO typically affects older horses, younger horses may have a less severe form of the disease. There is also evidence of a relationship between other inflammatory airway disease in young performance horses and RAO in older horses. All breeds of horses are affected.

Although it is believed that RAO develops from allergic reactions, researchers still question why the other 80 percent of horses worldwide are not susceptible to the allergic airway response even though they may be exposed to the same allergens