Epistaxis – nosebleeds -is an important problem in racehorses. The bleeding occurs most commonly during the extreme conditions of a race. A blood vessel bursts inside the breathing apparatus in the head and blood flows down into the windpipes causing the affected horse to pull up and be unable to continue to gallop effectively.
No one knows exactly what causes nosebleeds – epistaxis – and effective treatment is difficult. Vets commonly use drugs that enhance the elimination of water from the body (diuretics) which help prevent the problem but do not treat the cause of the problem which is related to a weakness in the lining of blood vessels inside the head