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

[RolloTomasi]

Originally Posted by Riot

Microscopic bleeding is indeed the big deal. It causes small airway and alveoli scarring, impedes their breathing, sets them up for lung infections, pneumonia, fear of running. This is precisely why we use lasix in most horses! Not just to keep from looking at massive, uncontrolled bleeding which is only visible in the larger airways.

Are you suggesting that furosemide stops microscopic bleeding?

[Riot]

Originally Posted by RolloTomasi

Are you suggesting that furosemide stops microscopic bleeding?

Yes. Research shows a decrease in red blood cells and hemosiderophages via transtracheal washes post lasix vs. without lasix.

Diagnosing EIPH gives vastly different incident percentages depending upon the method: visual assessment by laypeople vs visual assessment by vet vs. bronchoscopy vs. transtracheal wash (TTW) or bronchoalveolar levage (BAL).

The gold standard is something we don't do on the track, BAL or TTW.

We do use bronchoscopy, but it misses evidence of lower airway bleeding, only detecting visible blood that has been moved up into the upper airways.

[RolloTomasi]

Originally Posted by Riot

Yes. Research shows a decrease in red blood cells and hemosiderophages via transtracheal washes post lasix vs. without lasix.

Is decreasing the severity of bleeding the same as stopping bleeding?

[Riot]

Originally Posted by RolloTomasi

Is decreasing the severity of bleeding the same as stopping bleeding?

Not necessarily - sometimes lasix makes it less, sometimes it makes it stop completely, sometimes it doesn't do anything. Overall yes, lasix vastly reduces the incidence of detection of bleeding due to EIPH in horses, including stopping it in some horses.

Here's a cross section of lung (viewing it from the horses left side, the front of the horse is on the left) showing where bleeding occurs, the top (dorsal) back (caudal) part of the lung. We only detect blood when it comes out of the lungs up into the trachea. The trachea isn't shown here, it would be to the left of the lungs:





Here's a horse bleeding so bad blood is bubbling out of the lungs, up the trachea, and out the nose. Only 1 out of 20 will bleed so badly this is seen:



Here's a horse with a little blood in the trachea via bronchoscopy:

[RolloTomasi]

Originally Posted by Riot

Overall yes, lasix vastly reduces the incidence of detection of bleeding due to EIPH in horses, including stopping it in some horses.

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

[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.

[Riot]

Cannon wrote: I have no doubt that horses treated aggressively with gastrogard for stomach ulcers perform far greater than those who arent treated but because those horses are not designated no one talks about that. Using the logic that some do, Gastrogard would be considered a performance enhancer as well.

That's a very good analogy, actually.

I cannot consider lasix a performance enhancer any more than preventative inhaler asthma meds are for a running athlete who happens to have asthma. Lasix enables a horse to run to their peak, by helping prevent the development of a medical condition that will inhibit running ability by suffocating the horse in it's own blood to a lesser or greater degree.

[Rupert Pupkin]

Originally Posted by Riot

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.

Speaking of pollution that the horses are breathing, I know that it would be expensive but wouldn't it be much better for the horses' lungs if the barn areas were re-done at all the tracks. At most tracks, the whole barn area is dirt. Why not put grass down everywhere and then pave the paths with that rubber brick stuff. Inside the barns, they could put down that rubber brick surface too.

I would have to think the horses would be less likely to bleed if their lungs weren't filled with all the dust that they breathe in all day in the barn area.

At Oaklawn Park they have a lot of grass in the barn areas. I would have to think that is much better than all that dirt and dust.