Airway Disease Workshop Gathers World's Leading Researchers

The first International Workshop on Equine Chronic Airway Disease was held in mid-June at Michigan State University. Thirty of the world's leading investigators of equine airway disease met, along with representatives of pharmaceutical companies, writes Stephanie Church in the September edition of The Horse.

The participants reached agreement on several important issues: terminology, criteria for defining research populations, and methodology for obtaining samples.

"Because there isn't a lot of money for this kind of research, it doesn't make sense for us to duplicate each other's laboratories, some of which have very specialized technology," said Dr. Edward Robinson, the Matilda R. Wilson Professor of Large Animal Clinical Sciences at Michigan State and the organizer of the workshop. "It's much better for us to build on our strengths and to share the research material around the world."

One recommendation of the group was that the term "chronic obstructive pulmonary disease" or COPD no longer be used to refer to equine chronic airway disease. The human disease referred to as COPD bears little resemblance to the horse disease of the same name.

"There is no question there is a real need to try to bring some semblance of commonality to the nomenclature that is used to describe chronic equine pulmonary diseases around the world," said Dr. Warwick M. Bayly of Washington State University. "There are clearly differences in meaning between the use of the same terms by researchers and practitioners. Consistency in the use of these terms will probably only come about when and if veterinary students are being taught the same thing with regard to disease definition, characteristics, and diagnosis. The first step in this regard is to agree on what is meant by terms like 'recurrent airway obstruction (RAO),' airway disease, and COPD."

RAO was agreed upon to describe the severe airway obstruction of mature horses that is reversed by changes in environment or by use of bronchodilators. "Inflammatory airway disease" will be used to describe airway inflammation in younger horses, often in racehorses in training.

The group also made a strong recommendation against the use of certain diagnostic tests that involve measurements of the immune system. Robinson explained that the immunopathology of heaves is unclear, and the role of allergies is undefined. If heaves is an immune response to factors in the environment, the production of antibodies is most likely localized in the lung, and not reflected in tests made on plasma or the skin. The use of skin testing and desensitization is not supported by science.

"Treatment options we do know to be effective are environmental modifications and use of corticosteroids and bronchodilators," Robinson said.