bleeder

A horse that bleeds from the lungs when small capillaries that surround the lungs' air sacs (alveoli) rupture. The medical term is "exercise-induced pulmonary hemorrhage" (EIPH). Blood may be seen coming out of the horse's nostrils, known as "epistaxis," although it is typically discovered by a fiber optic endoscopic examination after exercise. Hot, humid weather and cold are known to exacerbate the problem. The most common preventative treatment currently available is the use of the diuretic furosemide (Lasix). Less than one bleeder in 20 shows signs of epistaxis. See "Exercise-Induced Pulmonary Hemorrhage" subsection of "Respiratory System" in veterinary supplement for a more detailed explanation.