Is horse lung bleeding (EIPH) caused by the force of galloping?

There have been articles in veterinary journals including a theory that lung bleeding occurs due to the force of the impact transmitted through the forelimbs of the horse as they strike the ground. It is most unlikely or impossible that horses with such a type of constitutional weakness could have survived evolution. There have never been any reports of bleeding in wild horses.

EIPH or lung bleeding is common in dressage horses and known in dray horses, where there is little impact of the hoofs on the ground. We have seen horses with high blood pressure who bleed if they are just walked.

The cause of the bleeding is now known with certainty to be extra high blood pressure when the horse is under exertion. A healthy horse at rest has a pulse of 40 to 50 beats per minute, but rising to over 250 beats at maximum effort, accounting for the horse's superb speed and acceleration. It is normal for blood pressure to rise during exertion in a healthy horse. This pressure is supported by veins inside the hoof which are compressed by the pressure on the digital cushion. Blood is thereby 'pumped' up the leg.

In the bleeding horse the blood pressure rises higher than normal and the result is burst blood vessels in the lung. Equiwinner is the only product which effectively returns blood pressure to optimum, solving the bleeding problem.