Recurrent Airway Obstruction (RAO), also called severe asthma or heaves, is a chronic disease in adult horses caused by aeroallergens from straw or hay. Disturbances in hemostasis (intensified coagulation and depressed fibrinolysis) are considered one of the prominent reasons of inflammatory process, injury and dysfunction of the lungs. The aim of the study was to evaluate chosen parameters of hemostasis in horses with active form of RAO. Ten RAO-horses (group R) and ten healthy horses (group C) were exposed to straw and hay allergen challenge. The prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), fibrinogen concentration (Fb), stabilized fibrin degradation product (d-dimer), antithrombin (AT), protein C and coagulation factors II through XII were assessed in plasma obtained from blood of all the horses. Exposure to aeroallergens resulted in prolongation of aPTT in both groups of animals; it was evident in the group R and moderate in the group C. There were no differences in PT and TT. Concentrations of fibrinogen and d-dimer and activity of protein C in both groups were increased but lay within or near to reference values. The activity of AT was depressed in RAO-horses. All exposed horses showed increased activity of coagulation factors II, VIII and X but they had no changes in activity of factor V. Factors VII and XII displayed a reduction in activity. The decrease in factor IX activity was noted in the group C only. Various changes were observed in activity of factor XI; in horses with RAO it was elevated but in healthy horses it was declined. The changes of the parameters tested in RAO-horses indicate the involvement of coagulation and fibrinolysis which apparently remained under control of efficient and active mechanisms of general hemostasis.

反复发作的气道阻塞（RAO），也称为重度哮喘或高潮，是成年马中由稻草或干草产生的气敏性过敏原引起的一种慢性疾病。止血障碍（凝血功能增强和纤维蛋白溶解抑制）被认为是炎症过程，肺损伤和功能障碍的重要原因之一。这项研究的目的是评估具有RAO活性形式的马的止血参数。将十只RAO马（R组）和十只健康马（C组）暴露于秸秆和干草过敏原激发下。凝血酶原时间（PT），活化部分凝血活酶时间（aPTT），凝血酶时间（TT），纤维蛋白原浓度（Fb），稳定的纤维蛋白降解产物（d-二聚体，抗凝血酶（AT），蛋白C和凝血因子II至XII在从所有马匹血液中获得的血浆中进行评估。暴露于气态变应原导致两组动物的aPTT延长。在R组中很明显，在C组中是中等的。PT和TT没有差异。纤维蛋白原和d的浓度两组中β-二聚体和蛋白C的活性均增加，但是处于参考值之内或附近。在RAO马中，AT的活性降低。所有暴露的马均显示凝血因子II，VIII和X的活性增加，但凝血因子V的活性没有变化。凝血因子VII和XII的活性降低。仅在C组中注意到因子IX活性的降低。XI因子的活性观察到各种变化；患有RAO的马的血脂水平升高，而健康马的血脂下降。在RAO马中测试的参数的变化表明了凝血和纤维蛋白溶解的参与，它们显然仍处于一般止血的有效和主动机制的控制之下。