Researcher Studies the Effect of Viral Infection on Allergic Airway
Diseases in Horses
ROUGELSU 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.
study is an evolution of many things weve been investigating
to understand equine airway disease. Its become pretty obvious
that RAO disorders are a result of allergic reactions," said
Dr. David Horohov, principal investigator and professor of veterinary
immunology. "With this study, were hoping to provide
insight into the consequence of early viral exposure and the tendency
of horses to develop allergic immune response in their lungs,"
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.
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.
is currently believed that exposure to infectious agents early in
life may help prevent later allergic complications. In other related
studies, heavily parasitized horses were protected, while other
horses were more susceptible to the development of allergic airway
response. According to Horohov, this is similar to what may be seen
in humans in underdeveloped countries. "Asthma problems were
not typical in underdeveloped countries until the incidence of parasitism
and other infectious diseases was reduced through the use of modern
drugs and vaccinations," he said.
has also become clear through research that the programming of children
for allergic diseases happens early on, and it is believed a similar
situation occurs in horses to predispose airway problems.
the past research into consideration and hoping to clarify new questions,
the study will focus on the immune function of the foals respiratory
system with two approaches. The first part of the study will focus
on the immunologic capability of the foals lung during the
first year of life. The second part will determine what effect a
viral infection will have on the lungs immune responsiveness.
Dale Paccamonti, Dennis French and Ralph Beadle from the Department
of Veterinary Clinical Sciences are co-investigators of the study.
This study is one of 22 research projects sponsored this year by
the Grayson-Jockey Club Research Foundation of Lexington, Ky., which
funds equine health research. Horohov received $57,680 for the first
year of study and will receive $70,000 for the second year.
is the second study Horohov has conducted through the assistance
of Grayson-Jockey Club. The first study explored Summer Pasture-Associated
Obstructive Pulmonary Disorder, a form of equine RAO that affects
horses in the southern United States. He determined that the disorder
is a result of an allergic response to inhaled allergens. The current
study hopes to identify immunological events that lead to the allergic
response in the affected horses.