EVIDÊNCIA DE HEMORRAGIA PULMONAR INDUZIDA PELO EXERCÍCIO EM CAVALOS DE SALTO DE 1,00 M – 1,20 M

Abstract

The present study evaluated the occurrence of exercise-induced pulmonary hemorrhage (EIPH) in jumping horses of 1.00 m - 1.20 m. Seven horses were evaluated three times. Two of the evaluations were performed with airway endoscopy 60 minutes after the second day of competition. Following endoscopy, animals were sedated for the collection of bronchoalveolar lavage (BAL) fluid, instilling 300 mL of sterile saline prewarmed at 37oC and immediately aspirated. The samples were centrifuged, the cell pellet was used for total nucleated cell count (TNCC), total erythrocyte count and differential cytology. The third evaluation was performed after 50 days of rest following competitions. Presence of blood in the tracheal lumen was graded 0 to 4. Epistaxis was not observed in the evaluated horses. One animal showed grade 1 of EIPH. BAL fluid TNCC was higher in the second evaluation in comparison with the first one (83.0 ± 34.8 vs. 55.0 ± 24.5 cells/µL BAL fluid, p = 0.017), reducing after 50 days of rest (15.5 ± 9.1 vs. 83.0 ± 34.8 cells/µL BAL fluid, p = 0.003). In the BAL differential cytology proceeded after 50 days of rest, there was a higher percentage of neutrophils in comparison with the first (25.9 ± 5.6% vs.17.7 ± 4.3%, p = 0.033) and second (25.9 ± 5.6% vs.7.6 ± 7.4%, p = 0.005) evaluations, indicating pulmonary inflammation after the period of competition. This was associated with EIPH, evidenced by the increased number of erythrocytes in BAL fluid of the second evaluation in comparison with the first (5.2 ± 3.1 vs. 0.9 ± 0.4 erythrocytes/µL BAL fluid, p = 0.048) and increased percentage of hemosiderophages after 50 days of rest (p = 0.032). It was concluded that horses performing submaximal exercise are prone to EIPH and it is associated with pulmonary inflammation.