<P> Furosemide (trade name: Lasix) administered prior to racing or strenuous exercise in Thoroughbred and Standardbred racehorses reduces the severity EIPH in 68% of horses . Up to 85% of Thoroughbred racehorses in the United States have been administered furosemide at least once during their racing career . Furosemide decreases pulmonary arterial pressure via its diuretic effects, bronchodilates, and redistributes blood flow during exercise . It reduces EIPH ranging from 90% at sub-maximal exercise and about 50% at maximal exercise intensities . However, over time, it causes electrolyte imbalances and has reduced effectiveness . Furosemide is prohibited in competing horses in some countries, and by the International Olympic Committee . The United States and Canada are the only countries which permit furosemide use during racing . </P> <P> Other vascular agents such as nitric oxide (NO), n - nitro - l - arginine methyl ester (L - Name), nitroglycerin, NO + phosphodiesterase inhibitors (e.g., sildenafil), and endothelin receptor antagonists have no effect, and in some cases worsen of the EIPH . </P> <P> A non-pharmacological nasal strip, applied prophylactically, variably reduces EIPH, depending on the severity of EIPH in an individual horse, and the duration and intensity of the exercise bout . The strip minimizes the increase in resistance to breathing, and the work of breathing as exercise intensity increases . There is synergy with the nasal strip in combination with furosemide . The strip has a spring - like action that mechanically supports and maintains the size of the nasal passage at its narrowest part, the nasal valve . Resistance to breathing doubles during intense or long - duration endurance exercise, with> 50% of the total resistance originating at the nasal passages . Decreased resistance reduces the airway forces across the pulmonary capillary membrane, reducing the EIPH . Use of the strip is permitted by the FEI, and in U.S. horse racing . </P> <P> Bronchodilatation is already maximized in the exercising horse, therefore bronchodilatory agents such as ipratropium, albuterol, or clenbuterol are not effective in reducing EIPH . </P>

Treatment of exercise induced pulmonary hemorrhage in horses