Kentucky's ongoing attempt to end racing in state proceeds..

[Riot]

Originally Posted by RolloTomasi

So the majority of horses treated with lasix do not bleed?

The majority have their previously documented level of bleeding markedly decreased or gone, as evidenced by bronchoscopy clinically and BAL/TTW in research. Lasix does not work in all horses, some are unaffected.

The origins and causes of EIPH are thought to be multifactorial. In the 1990's I worked on the research that first measured actual cardiopulmonary intravascular pressures in horses while galloping at racing speed both on and off lasix. Lasix decreases the exercise-induced increase in cardiac and pulmonary pressures. High blood pressure rupturing fragile capillaries in the lung has always been one suspected cause of EIPH.

Chronic airway inflammation predisposing to capillary failure is another. I'd love to study the lungs of horses that live year-round at Churchill Downs, bordered by highways and under airport plane exhaust.

Another is the physical pounding, and physics: the sheer forces created within the lung tissue as a horse gallops a long time over firm ground carrying weight.

Another is the huge variance in intrapulmonary airway pressures, upper vs lower, during massive air intake of exercise - why the Flair nasal strips which hold the upper airway open decrease EIPH as much as lasix in some horses.