Lung bleeding, also known as Exercise Induced Pulmonary Hemorrhage (EIPH), can go undetected by trainers and riders because it occurs deep within the lungs. Numerous studies show that essentially all horses experience some degree of EIPH during intensive exercise. However, only 5% of horses show blood at the nostrils.
To explain why lung bleeding happens, we have created this video:
EIPH occurs when fragile pulmonary blood vessels in the lungs rupture during exercise. Horses don't have to gallop to bleed. Research in Japan shows that horses only cantering at speeds of up to 20 mph (a very slow canter for a racehorse) all had damage to their lungs as a result of broken blood vessels. Some studies report that horses bleed even when doing mild exercise such as trotting on a treadmill.
Each time a horse does more than a slow canter, some blood vessels in the lung are broken. At first, this damage only affects a small area at the top back part of the lung; but, with repeated cantering, galloping and racing, the damage accumulates and affects more of the lung. The severity and frequency of bleeding observed by scoping after exercise or racing almost always increases with age.
Scar tissue forms in the lungs each time bleeding occurs. The blood vessels that break in the lung are almost always the blood vessels of the pulmonary circulation. When the vessels rupture, they may become blocked or not function normally. If the vessels are repaired, they may become stiff since scar tissue is not as flexible as normal healthy lung tissue. Damaged lung tissue, even if it is repaired, doesn’t function as well, leaving the horse’s lung capacity and function reduced.
The lung is a limiting factor for performance in horses; so, even small losses of lung function can have significant, unfavorable effects on performance and shorten a horse's competitive career.
Reducing bleeding not only helps a horse perform better in the short term, but it may also help long term by reducing the possibility of inflammatory airway disease and chronic lung damage due to repeated bleeding episodes.
FLAIR® Equine Nasal Strips are clinically proven to reduce lung bleeding during high intensity exercise. The Strips reduce bleeding by normalizing pressure across the pulmonary capillary membrane. Studies have shown that horses affected by EIPH that wear a FLAIR Strip have fewer blood cells in their airways after exercise compared to the same horses not wearing a Strip. The FLAIR Strip is a mechanical device, so it will be equally as effective every time it's used and can be used with every intensive work out.