Only racehorses get exercise-induced pulmonary hemorrhage (EIPH), right? Aren't they the only ones working hard enough to rupture blood vessels in their lungs? The answer to this question is not so simple. Research has shown that EIPH occurs in 80-100% of racehorses, but little EIPH research has been done on more moderately exercising horses. Since visible bleeding out of the nose (epistaxis) only occurs in 0.25-13% of sprinting horses, many less obvious bleeders might be escaping detection if their lungs are never examined endoscopically.

Why does this matter? Even if the horse isn't bleeding visibly, it can cause short- and long-term problems. A horse which is bleeding from the nose has ruptures of pulmonary (lung) blood vessels, possibly caused by increased pressure on those vessels. This increased pressure means that he's working harder to get the oxygen he needs, thus using more oxygen and fatiguing more quickly. Also, blood in his lungs causes an inflammatory response, with swelling that can further hamper lung performance. There also is scarring of lung tissue from repeated episodes of bleeding, which compounds the problem. Obviously, EIPH can become a vicious cycle.

One solution would be to cut the horse's exercise level back so that he doesn't breathe hard enough to rupture pulmonary vessels, or to use medications that help decrease pulmonary pressures (such as SALIX, formerly known as Lasix). Another solution could be something to reduce the amount of work it takes to breathe, thus reducing the pressure. Enter research on the external nasal dilator called the Flair nasal strip.

Opening the Nasal Passages

Obstructions in the nose and upper airway, such as tumors, can make it harder for a horse to breathe. Obstructions are not always obvious, however. A horse might have nasal tissues that collapse slightly or flutter when he inhales, which can hamper airflow without anyone noticing.

Nasal passage resistance is more of a problem in horses than in humans because horses can only breathe through their noses. Up to 50% of total pulmonary resistance might be from the nasal passages--thus, we can see how important nasal passage airflow is to the horse.

You've seen the advertisements for Breathe Right strips for humans who snore or feel that they need more airflow during exercise; the Flair nasal strip is the same thing, only designed for horses. It includes three plastic strips that act as springs when stuck across the horse's nose with medical-grade adhesive, opening the nasal passages wider. Craig Shoemaker, DVM, MS, Director of Veterinary Services at CNS, Inc., manufacturers of the Flair nasal strips, says, "Flair is an airway mechanism, preventing nasal passage collapse and decreasing transmural (involving the entire wall) lung pressure, which is involved in shearing forces in the lung capillaries. Horses still need to use the same amount of oxygen for athletic work, but less for breathing." (Less oxygen use means the horse isn't working as hard.)

Howard H. Erickson, DVM, PhD, professor of physiology at Kansas State University and a recipient of the American Veterinary Medical Association Bayer Excellence in Equine Research Award, presented a study on Flair nasal strips at the 2000 American Association of Equine Practitioners convention. He found that when horses wore Flair nasal strips for high-speed exercise, compared to exercise without the strips, they consumed a significantly lower amount of oxygen, produced less carbon dioxide (another indicator of less energy use by the muscles), and had 33% less blood cells found in bronchoalveolar lavage (BAL) fluid.

This lower oxygen consumption results in less fatigue and a quicker recovery after exercise, while the decreased bleeding indicates less stress on lung tissues (and less blood in the lungs to induce inflammation). Additional studies by Erickson and Ray Geor, BVSc, PhD, Dipl. ACVIM, have repeated these results.

"In veterinary medicine, something almost has to come in a syringe for people to think it works," Shoemaker comments. "But this is medical treatment based on scientific proof."

Flair strips would seem to be an acceptable alternative or additional treatment to furosemide (SALIX), which has been used to combat EIPH in the past. Furosemide works as a diuretic, increasing elimination of water from the body and thereby decreasing blood volume and blood pressure.

Shoemaker considers the Flair strips a preventive health maintenance tool in addition to medical treatment for known bleeders. "If I was in the training business, I'd look at Flair as an adjunct tool to protect my investment in a horse's future performance and pulmonary health," he says. "It can be viewed both as a preventive for the 'normal' horse by decreasing cumulative stress on the capillaries, and a treatment for the horse with a known bleeding problem."

The Flair strips can be left on for a full day of work, and have been used by top competitors in racing, eventing, reining, and polo. During a time when medications in competition horses are being increasingly scrutinized, a proven effective, non-medical treatment (and preventive) for EIPH might be just the thing for owners of affected horses.

About the Author

Christy M. West

Christy West has a BS in Equine Science from the University of Kentucky, and an MS in Agricultural Journalism from the University of Wisconsin-Madison.

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