Evaluation of horses submitted to exercise on treadmill with occlusion of the jugular vein by induced thrombosis treated or not with streptokinase

Abstract

Thrombophlebitis of the jugular vein is a frequently encountered condition in horses. To date, no studies about sanguineous and circulatory evaluation in horses during exercise with external jugular vein occlusion by thrombus have been published. Also, there are no reports concerning the treatment for jugular thrombophlebitis in horses using regional thrombolytic therapy with streptokinase. The purpose of this study is to document clinical, ultrasonographic, hemodynamic, hematimetric and hemogasometric changes in equines submitted to unilateral external jugular vein occlusion by venous thrombus induced by extravascular administration of phenilbutazone. The evaluations will be performed before, during and after progressive exercise on treadmilll. After the adaptative period to treadmill, the horses will be ramdomized in three groups: GI, GII e GIII. All horses will be submitted to induction of aseptic jugular thrombophlebitis and ultrasonography of the jugular vein will be performed every 12 hours to identify the moment of occlusion. GI will be the control group (not treated); GII will be treated with streptokinase 24 hours after ultrasonographic identification of occlusion (simulating acute disease); GIII will be treated with streptokinase 72 hours after ultrasonographic identification of occlusion (simulating chronic disease). Thrombus dissolution will be followed by ultrasonography and anticoagulant therapy with heparin will be realized to avoid new thrombus formation. All the groups will be submitted to exercise on treadmill to obtain blood samples during this activity. The results will be analyzed by variance analysis test (ANOVA) using the software Sigma Stat. (AU)