Exercise-induced pulmonary haemorrhage in horses – review

Abstract

Exercise-induced pulmonary haemorrhage is a major cause of poor performance in the equine athlete. It is an important cause of exercise intolerance and results from strenuous exercise and pathophysiological changes in the equine lung and possibly in the airways. Endoscopic surveys of the respiratory tracts of horses after competitive events have shown that many horses experience exercise-induced pulmonary haemorrhage. The reported incidence of exercise-induced pulmonary haemorrhage in different breeds varies between 40-85%. The cause of bleeding in exercising horses has fostered considerable debate over the past three centuries, but currently, the most accepted hypothesis is that the source of haemorrhage is disruption of the pulmonary capillaries during exercise. Furosemide is the medication used most widely for the treatment and prevention of exercise-induced pulmonary haemorrhage. This review provides an update on the aetiology, clinical signs, physiopathology, diagnosis and treatment of exercise-induced pulmonary haemorrhage. EIPH, pulmonary pressure, equine

Suspected postoperative phenylephrine‐associated pulmonary haemorrhage in a horse with nephrosplenic entrapment of the large colon

“…14,15 It is also possible that the mechanism developed is similar to the exercise-induced pulmonary haemorrhage described in horses, in which severe exercise produces an excessive increase in pulmonary pressures, leading to pulmonary haemorrhage. 26 In conclusion, this case shows a delayed and unusual presentation of pulmonary haemorrhage, likely secondary to phenylephrine administration, compared to other cases reported. The exact cause of pulmonary haemorrhage, as well as the exact moment bleeding started, remained unknown.…”

“…However, this theory does not completely explain the spontaneous bleeding that has been seen in the younger horses 14,15 . It is also possible that the mechanism developed is similar to the exercise‐induced pulmonary haemorrhage described in horses, in which severe exercise produces an excessive increase in pulmonary pressures, leading to pulmonary haemorrhage 26 …”

A 31-Year-Old Female With Postcoital Hemoptysis

“…Exercise-induced pulmonary hemorrhage, commonly presenting as epistaxis, is a well-known phenomenon occurring in most breeds of racehorses after competitive events [2]. It is most likely due to the sharp rise in pulmonary artery wedge pressures and pulmonary capillary pressures that accompany the marked increase in cardiac output, sometimes exceeding 30 L/min, during vigorous exercise.…”

A comparison of haematological and biochemical blood indices between the Žemaitukai and Arabian horses participating in endurance competitions

“…The RBC appear to act as a buffer against any exercise-related increase in plasma potassium and any decrease in blood pH since the uptake of potassium into the cell and the exchange of bicarbonate with chloride may be beneficial to performance but can lead to erythrocyte swelling (Masini et al 2000). The RBC swelling also reduces the surface-to-volume ratio, thereby decreasing cell deformability, which is expected to increase capillary wall shear stress, possibly contributing to that capillary rupture that is associated with exercise-induced pulmonary haemorrhage (Morán and Folch 2013).…”